The Q source (also called Q document, Q Gospel, or Q from German: Quelle, meaning "source") is a hypothetical written collection of primarily Jesus' sayings (logia). Q is part of the common material found in the Gospels of Matthew and Luke but not in the Gospel of Mark. According to this hypothesis, this material was drawn from the early Church's oral tradition.
Along with Marcan priority, Q was hypothesized by 1900, and is one of the foundations of most modern gospel scholarship. B. H. Streeter formulated a widely accepted view of Q: that it was written in Koine Greek; that most of its contents appear in Matthew, in Luke, or in both; and that Luke more often preserves the text's original order than Matthew. In the two-source hypothesis, the three-source hypothesis and the Q+/Papias hypothesis, Matthew and Luke both used Mark and Q as sources. Some scholars have postulated that Q is actually a plurality of sources, some written and some oral. Others have attempted to determine the stages in which Q was composed.
Q's existence has been questioned. Omitting what should have been a highly treasured dominical document from all early Church catalogs, its lack of mention by Jerome is a conundrum of modern Biblical scholarship. But copying Q might have been seen as unnecessary as it was preserved in the canonical gospels. Hence, it was preferable to copy the Gospels of Matthew and Luke, "where the sayings of Jesus from Q were rephrased to avoid misunderstandings, and to fit their own situations and their understanding of what Jesus had really meant". Despite challenges, the two-source hypothesis retains wide support.
For centuries, biblical scholars followed the Augustinian hypothesis: that the Gospel of Matthew was the first to be written, Mark used Matthew in the writing of his, and Luke followed both Matthew and Mark in his (the Gospel of John is quite different from the other three, which because of their similarity are called the Synoptic Gospels). Nineteenth-century New Testament scholars who rejected Matthew's priority in favor of Marcan priority speculated that Matthew's and Luke's authors drew the material they have in common with the Gospel of Mark from Mark's Gospel. But Matthew and Luke also share large sections of text not found in Mark. They suggested that neither Gospel drew upon the other, but upon a second common source, termed Q.
Herbert Marsh, an Englishman, is seen by some as the first person to hypothesize the existence of a "narrative" source and a "sayings" source, although he included in the latter parables unique to Matthew and unique to Luke. In his 1801 work, A dissertation on the Origin and Composition of our Three First Canonical Gospels, he used the Hebrew letter Aleph (א) to denote the narrative source and the letter beth (ב) to denote the sayings source.
The next person to advance the "sayings" hypothesis was the German Friedrich Schleiermacher in 1832. Schleiermacher interpreted an enigmatic statement by the early Christian writer Papias of Hierapolis, c. AD 95–109 ("Matthew compiled the oracles (logia) of the Lord in a Hebrew manner of speech, and everyone translated them as well he could") as evidence of a separate source. Rather than the traditional interpretation—that Papias was referring to the writing of Matthew in Hebrew—Schleiermacher proposed that Papias was actually referring to a sayings collection of the apostle Matthew that was later used, together with narrative elements, by another "Matthew" and by the other Evangelists.
In 1838 another German, Christian Hermann Weisse, took Schleiermacher's suggestion of a sayings source and combined it with the idea of Marcan priority to formulate what is now called the Two-Source Hypothesis, in which both Matthew and Luke used Mark and the sayings source. Heinrich Julius Holtzmann endorsed this approach in an influential treatment of the synoptic problem in 1863, and the two-source hypothesis has dominated ever since.
At this time, the second source was usually called the Logia, or Logienquelle (logia-source), because of Papias's statement, and Holtzmann gave it the symbol Lambda (Λ). But toward the end of the 19th century, doubts began to grow about the propriety of anchoring its existence to Papias's account. So the symbol Q (which was devised by Johannes Weiss to denote Quelle, meaning source) was adopted to remain neutral about the connection of Papias to the collection of sayings.
This two-source hypothesis speculates that Matthew borrowed from both Mark and Q. For most scholars, Q accounts for what Matthew and Luke share—sometimes in exactly the same words—but that are absent in Mark. Examples are the Devil's three temptations of Jesus, the Beatitudes, the Lord's Prayer, and many individual sayings.
In The Four Gospels: A Study of Origins (1924), Burnett Hillman Streeter argued that a third hypothetical source, referred to as M, lies behind the material in Matthew that has no parallel in Mark or Luke, and that some material present only in Luke might have come from an also unknown L source. This hypothesis posits that underlying the Gospels of Matthew and Luke are at least four sources, namely the Gospel of Mark and three lost texts: Q, M, and L. (M material is represented by green in the above chart, and L by blue.)
Throughout the remainder of the 20th century, there were various challenges and refinements of Streeter's hypothesis. For example, in his 1953 book The Gospel Before Mark, Pierson Parker posited an early version of Matthew (Aramaic M or proto-Matthew) as the primary source. Parker argued that it was not possible to separate Streeter's "M" material from the material in Matthew parallel to Mark.
In the early 20th century, more than a dozen reconstructions of Q were made. But these reconstructions differed so much from each other that not a single verse of Matthew was present in all of them. As a result, interest in Q subsided and it was neglected for many decades.
This state of affairs changed in the 1960s after translations of a newly discovered and analogous sayings collection, the Gospel of Thomas, became available. James M. Robinson of the Jesus Seminar and Helmut Koester proposed that collections of sayings such as Q and Gospel of Thomas represented the earliest Christian materials at an early point in a trajectory that eventually resulted in the canonical gospels. This burst of interest after the discovery of the Gospel of Thomas led to increasingly more sophisticated literary reconstructions of Q.
Redactional speculation, notably in the work of John S. Kloppenborg analyzing certain literary and thematic phenomena, argued that Q was composed in three stages. In his view, the earliest stage was a collection of wisdom sayings involving such issues as poverty and discipleship. Then, he posits, this collection was expanded by including a layer of judgmental sayings directed against "this generation". The final stage included the Temptation of Jesus narrative.
Although Kloppenborg cautioned against assuming that Q's composition history is the same as the history of the Jesus tradition (i.e., that the oldest layer of Q is necessarily the oldest and pure-layer Jesus tradition), some recent seekers of the Historical Jesus, including members of the Jesus Seminar, have done just that. Basing their reconstructions primarily on the Gospel of Thomas and the oldest layer of Q, they propose that Jesus functioned as a wisdom sage, rather than a Jewish rabbi, though not all members affirm the two-source hypothesis. Kloppenborg is now a fellow of the Jesus Seminar himself.
But scholars supporting the three-stage Q development hypothesis, such as Burton L. Mack, argue that Q's unity comes not only from its being shared by Matthew and Luke, but also because, in the layers of Q as reconstructed, the later layers build upon and presuppose the earlier ones, whereas the reverse is not the case. So evidence that Q has been revised is not evidence for disunity in Q, since the hypothesised revisions depend upon asymmetric logical connections between what are posited to be the later and earlier layers.
Some biblical scholars believe that an unknown redactor composed a Greek-language proto-Gospel. It may have been circulating in written form about the time the Synoptic Gospels were composed (i.e., between late 50s and mid 90s AD). The name Q was coined by the German theologian and biblical scholar Johannes Weiss.
Synoptic Gospels and the nature of Q
The relationship among the three synoptic gospels goes beyond mere similarity in viewpoint. The gospels often recount the same stories, usually in the same order, sometimes using the same words. Scholars note that the similarities between Mark, Matthew, and Luke are too great to be coincidental.
If the two-source hypothesis is correct, then Q would probably have been a written document. If Q was a shared oral tradition, it is unlikely that it could account for the nearly identical word-for-word similarities between Matthew and Luke when quoting Q material. Similarly, it is possible to deduce that Q was written in Greek. If the Gospels of Matthew and Luke were referring to a document that had been written in some other language (Aramaic for example), it is highly unlikely that two independent translations would have exactly the same wording.
The Q document must have been composed before Matthew and Luke. Some scholars even suggest that Q predated Mark. A date for the final Q document is often placed in the 40s or 50s of the first century, with some arguing its so-called sapiential layer (1Q, containing six wisdom speeches) was written as early as the 30s.
If Q existed it has since been lost. Some scholars believe it can be partially reconstructed by examining elements common to Matthew and Luke (but absent from Mark). This reconstructed Q does not describe the events of Jesus' life: Q does not mention Jesus' birth, his selection of the 12 disciples, his crucifixion, or the resurrection. Instead, it appears to be a collection of Jesus' sayings and quotations.
Case for Q
The case for Q's existence follows from the argument that neither Matthew nor Luke is directly dependent on the other in the double tradition (defined by New Testament scholars as material that Matthew and Luke share that does not appear in Mark). But the verbal agreement between Matthew and Luke is so close in some parts of the double tradition that the most reasonable explanation for this agreement is common dependence on a written source or sources. Even if Matthew and Luke are independent (see Marcan priority), the Q hypothesis states that they used a common document. Arguments for Q being a written document include:
- Sometimes the exactness in wording is striking, for example, ‹See Tfd›Matthew 6:24 = ‹See Tfd›Luke 16:13 (27 and 28 Greek words respectively); ‹See Tfd›Matthew 7:7–8 = ‹See Tfd›Luke 11:9–10 (24 Greek words each).
- There is sometimes commonality in order between the two, for example the Sermon on the Plain and Sermon on the Mount.
- The presence of doublets, where Matthew and Luke sometimes each present two versions of a similar saying but in different context, only one of those versions appearing in Mark. Doublets may be considered a sign of two written sources, i.e., Mark and Q.
- Luke mentions that he knows of other written sources of Jesus' life, and that he has investigated in order to gather the most information.
The fact that no Q manuscripts exist today does not necessarily argue against its existence. Many early Christian texts no longer exist, and we only know they did from their citation or mention in surviving texts. Once Q's text was incorporated into the body of Matthew and Luke, it was no longer necessary to preserve it, just as interest in copying Mark seems to have waned substantially once it was incorporated into Matthew. The editorial board of the International Q Project writes: "During the second century, when the canonizing process was taking place, scribes did not make new copies of Q, since the canonizing process involved choosing what should and what should not be used in the church service. Hence they preferred to make copies of the Gospels of Matthew and Luke, where the sayings of Jesus from Q were rephrased to avoid misunderstandings, and to fit their own situations and their understanding of what Jesus had really meant."
Case against Q
While the two-source hypothesis remains the most popular explanation for the synoptic gospels' origins, the existence of the "minor agreements" has raised serious concerns. These minor agreements are those points where Matthew and Luke agree against or beyond Mark precisely within their Marcan verses (for example, the mocking question at the beating of Jesus, "Who is it that struck you?" [Luke 22:64/Matthew 26:68], found in both Matthew and Luke but not in Mark, although this "minor agreement" falls outside the usually accepted range of Q.) The "minor agreements" call into question the proposition that Matthew and Luke knew Mark but not each other, e.g. Luke might have indeed been following Matthew, or at least a Matthew-like source. Peabody and McNicol argue that until a reasonable explanation is found the two-source hypothesis is not viable.
New Testament scholar James Edwards argues that the existence of a treasured sayings document in circulation going unmentioned by early Church Fathers remains one of the great conundrums of modern Biblical scholarship. Pier Franco Beatrice argues that until these issues are resolved, Q will remain in doubt.
Some scholars argue that the Gospel according to the Hebrews was the basis for the synoptic tradition. They point out that in the first section of De Viris Illustribus (Jerome), the Gospel of Mark is where it should be as it was the first gospel written and was used as a source for the later gospels. Following it should be Q. But not only is Q not where it should be at the top of Jerome's list, this treasured work recording the Logia of Christ is mentioned nowhere by Jerome. Rather, the first seminal document is not Q but the Gospel according to the Hebrews.
Austin Farrer, Michael Goulder, and Mark Goodacre have also argued against Q, maintaining Marcan priority, claiming the use of Matthew by Luke. This view has come to be known as the Farrer hypothesis. Their arguments include: Farrer, in his 1955 paper that first outlined this hypothesis, notes that when two documents contain common material, identical in the words and phrases they use to describe some scenes, the simplest explanation is that one of the two used the other as a source, rather than both using a third document as a source. Goulder points to common Matthean phrases such as "brood of vipers", "make fruit", and "cast into the fire" that each appear in Luke only once, in a Q passage. Goulder's conclusion, based on writing styles, is that Matthew is the source for these "Q" sayings. Goodacre notes that there is no extant copy of Q and that no early church writer makes an unambiguous reference to a document resembling the Q that modern scholars have reconstructed from the common material in Luke and Matthew.
While supporters say that the discovery of the Gospel of Thomas supports the concept of a "sayings gospel", Mark Goodacre points out that Q has a narrative structure as reconstructed and is not simply a list of sayings.
Other scholars have brought other arguments against Q: Two documents, both correcting Mark's language, adding birth narratives and a resurrection epilogue, and adding a large amount of "sayings material", are likely to resemble each other, rather than to have such similar scope by coincidence. Specifically, there are 347 instances (by Neirynck's count) where one or more words are added to the Marcan text in both Matthew and Luke; these are called the "minor agreements" against Mark. Some 198 instances involve one word, 82 involve two words, 35 three, 16 four, and 16 instances involve five or more words in the extant texts of Matthew and Luke as compared to Marcan passages. John Wenham (1913–1996) adhered to the Augustinian hypothesis that Matthew was the first Gospel, Mark the second, and Luke the third, and objected on similar grounds to those who hold to the Griesbach hypothesis. Eta Linnemann, formerly a follower of Rudolf Bultmann, rejected Q, and Marcan priority, for a variation of the Two Gospel hypothesis that holds that the Mosaic requirement for "two witnesses" made two Jewish Gospels a necessity in the Diaspora audiences.
Some of the more notable portions of the New Testament are believed to have been first recorded in Q:
- Horsley, Richard A.; Draper, Jonathan A. (November 1999). Whoever Hears You Hears Me: Prophets, Performance, and Tradition in Q. A&C Black. p. 150–74. ISBN 9781563382727.
- Dunn, James D. G. (July 29, 2003). Jesus Remembered: Christianity in the Making. pp. 192–210. ISBN 9780802839312.
- Mournet, Terence C. (2005). Oral Tradition and Literary Dependency: Variability and Stability in the Synoptic Tradition and Q. pp. 54–99. ISBN 9783161484544.
- Funk, Robert W., Roy W. Hoover, and the Jesus Seminar. The Five Gospels. HarperSanFrancisco. 1993. "Introduction," pp. 1–30.
- Mournet, Terence C. (2005). Oral Tradition and Literary Dependency: Variability and Stability in the Synoptic Tradition and Q. pp. 192–286. ISBN 9783161484544.
- "'Q.'" Cross, F. L., ed. The Oxford Dictionary of the Christian Church. New York: Oxford University Press. 2005
- Edwards, James R. (October 16, 2009). The Hebrew Gospel and the Development of the Synoptic Tradition. p. 228. ISBN 9780802862341.
- (From the preface to the Sayings Gospel Q, International Q Project, 2001 http://homes.chass.utoronto.ca/~kloppen/iqpqet.htm)
- This hypothetical lost text—also called the Q Gospel, the Sayings Gospel Q, the Secret of Q, the Synoptic Sayings Source, the Q Manuscript, and (in the 19th century) The Logia—is said to have comprised a collection of Jesus' sayings. Acceptance of the theories of the existence of "Q" and the priority of Mark are the two key elements in the "two-source hypothesis". (See also the Gospel of the Hebrews and Streeter.)
- D. R. W. Wood, New Bible Dictionary (InterVarsity Press, 1996), 739.
- William R. Farmer, The Synoptic Problem, 1964, Macmillan, p. 14
- Hultgren, Stephen (2002). Narrative Elements in the Double Tradition. Walter de Gruyter. pp. 4–5.
- Yarbrough, Robert W. (June 1983). "The Date of Papias: A Reassessment" (PDF). Journal of the Evangelical Theological Society. 26 (2): 181–191.
- Hultgren, Stephen (2002). Narrative Elements in the Double Tradition: A Study of Their Place within the Framework of the Gospel Narrative. pp. 9–10. ISBN 9783110175257.
- Bart D. Ehrman, Jesus: Apocalyptic Prophet of the New Millennium, Oxford University Press, pp. 80–81
- Streeter, Burnett H. The Four Gospels. A Study of Origins Treating the Manuscript Tradition, Sources, Authorship, & Dates. London: Macmillan and Co., Ltd., 1924.
- Pierson Parker. The Gospel Before Mark. Chicago: University of Chicago Press, 1953.
- William R. Farmer, The Synoptic Problem: a Critical Analysis, Macmillan, 1981 p. 196
- Harrison, Everett Falconer (1964). Introduction to the New Testament. p. 152. ISBN 9780802847867.
- The Lost Gospel: The Book Q and Christian Origins, Macmillan Co. (1993, paperback 1994).
- "Britannica". Britannica. Retrieved April 15, 2012.
- Tony Honoré, "A Statistical Study of the Synoptic Problem." Novum Testamentum August 10 – July (1968): 95–147. On page 96 Honoré compares the similarities between the three Gospels with the number of words in common.
- *Ehrman, Bart D. (2004). The New Testament: A Historical Introduction to the Early Christian Writings. New York: Oxford. p. 84. ISBN 978-0-19-515462-7.
- Burkett, Delbert Royce (2009). Rethinking the Gospel Sources: The unity or plurality of Q. pp. 47–48. ISBN 9781589834125.
- Dunn, James D. G., Christianity in the Making Volume 1: Jesus Remembered. Grand Rapids, Michigan: Wm. B. Eerdmans, 2003. p. 159
- Luke 1:1–4
- Thomas, Robert L.; David Farnell, F. (1998). The Jesus Crisis: The Inroads of Historical Criticism into Evangelical Scholarship. pp. 136–140. ISBN 9780825438110.
- See C.M. Tuckett, "The Existence of Q", p. 19–48, in The Gospel Behind the Gospels: Current Studies on Q. Edited by R. Piper. Leiden: Brill, 1995 (espcially p. 20).
- Peabody, David B.; McNicol, Allan James; Cope, Lamar (November 2002). One Gospel from Two: Mark's Use of Matthew and Luke. A&C Black. p. 1–6. ISBN 9781563383526.
- Pier Franco Beatrice, The Gospel according to the Hebrews in the Apostolic Fathers Archived October 24, 2012, at the Wayback Machine, Novum Testamentum, 2006, vol. 48, no2, pp. 147–95 (ingentaconnect.com)
- Pierson Parker (December 1940). "A Proto-Lucan basis for the Gospel according to the Hebrews". Journal of Biblical Literature. 59 (4): 471–78. doi:10.2307/3262407. JSTOR 3262407.
- Lillie, Arthur (2005). The Gospel According to the Hebrews. Kessinger Publishing. pp. 111–34. ISBN 978-1-4253-7051-0.
- Jerome, Saint (1999). Ste. Jerome, On illustrious men 1:4. ISBN 9780813201009.
- Jerome, Saint (1999). Ste. Jerome, On illustrious men 3:1. ISBN 9780813201009.
- Austin M. Farrer, "On Dispensing with Q" in D. E. Nineham (ed.), Studies in the Gospels: Essays in Memory of R. H. Lightfoot (Oxford: Blackwell, 1955), pp. 55–88, reproduced at "On Dispensing With Q". Archived from the original on February 1, 2009. Retrieved October 15, 2011..
- For example, Michael Goulder, "Is Q a Juggernaut", Journal of Biblical Literature 115 (1996), pp. 667–81, reproduced at "Is Q a Juggernaut?". Archived from the original on July 8, 2007. Retrieved July 17, 2007..
- See, for example, Mark Goodacre, The Case Against Q: Studies in Marcan Priority and the Synoptic Problem (Harrisburg, PA: Trinity Press International, 2002)
- "Ten Reasons to Question Q". Markgoodacre.org. January 10, 2003. Retrieved April 15, 2012.
- These statistics are taken from an analysis by Walter M. Shandruk of Frans Neirynck's The Minor Agreements of Matthew of Luke and Mark with a Cumulative List, Leuven University Press, 1974. The results of Shandruk's analysis have been posted at http://neonostalgia.blogspot.com/2005/09/minor-agreements-against-mark.html.
- Robert L. Thomas Three views on the origins of the Synoptic Gospels 2002 pp. 255, 322 "Farnell's third axiom notes, quoting Linnemann, that the reason for four independent Gospels stems from the legal principle of Deuteronomy 19:15b: "[O]n the evidence of two or three witnesses a matter shall be confirmed.""
- Reconstruction of Q by the International Q Project.
- Clayton N. Jefford (1989). The Sayings of Jesus in The Teaching of the Twelve Apostles. ISBN 978-9004091276. Retrieved April 29, 2012.
- A. M. H. Saari (July 26, 2006). The Many Deaths of Judas Iscariot: A Meditation on Suicide. ISBN 9780203087480. Retrieved April 29, 2012.
- John S. Kloppenborg: Q, the Earliest Gospel: An Introduction to the Original Stories and Sayings of Jesus. Westminster John Knox Press, Louisville 2008, ISBN 978-0-664-23222-1
- Klaus-Stefan Krieger: Was sagte Jesus wirklich?. Vier Türme, Münsterschwarzach 2003, ISBN 3-87868-641-2
- Thomas R. W. Longstaff, Page A. Thomas: The Synoptic Problem. A Bibliography 1716–1988. New Gospel Studies 4. Mercer, Macon 1988, ISBN 0-86554-321-6
- Frans Neirynck, J. Verheyden, R. Corstjens: The Gospel of Matthew and the Sayings Source Q. A Cumulative Bibliography 1950–1995. Bibliotheca Ephemeridum Theologicarum Lovaniensium 140. 2 volumes, University Press, Leuven 1998, ISBN 90-6186-933-1
- David M. Scholer: Q Bibliography Supplement. Society of Biblical Literature Seminar papers. Scholars Press, Atlanta 1965–2003, ISSN 0160-7588. 127.1991, pp. 1ff.; 128.1992, pp. 1ff.; 129.1993, pp. 1ff.; 130.1994, pp. 1ff.; 131.1995, pp. 1ff.; 132.1996, pp. 1ff.; 133.1997, pp. 750–56; 134.1998, pp. 1005–12; Introduction
- Marcus J. Borg, Thomas Moore (Eds.): The Lost Gospel Q: The Original Saying of Jesus. Ulysses Press 1996, ISBN 1-56975-100-5
- Maurice Casey: An Aramaic Approach to Q: Sources for the Gospels of Matthew and Luke. Cambridge University Press 2002, ISBN 0-521-81723-4
- Adolf von Harnack: Sprüche und Reden Jesu. Hinrichs, Leipzig 1907
- Harry T. Fleddermann: Q: A Reconstruction and Commentary. Peeters Press, Leuven 2005, ISBN 9042916567
- Paul Hoffmann, Christoph Heil (Eds.): Die Spruchquelle Q. Studienausgabe Griechisch und Deutsch. Wissenschaftliche Buchgesellschaft, Darmstadt 2002 (2nd edition 2007 / 3rd edition 2009 / 4th edition 2013), ISBN 978-3-534-26266-3
- Frans Neirynck (Ed.): Q-synopsis. The Double Tradition Passages in Greek. Studiorum Novi Testamenti Auxilia 13. University Press, Leuven 1988 (2nd expanded edition 1995, 2001), ISBN 90-5867-165-8
- Athanasius Polag: Fragmenta Q. Neukirchener Verlag, Neukirchen-Vluyn 1979/1982, ISBN 3-7887-0541-8
- James M. Robinson u.a. (Eds.): Documenta Q. Peeters, Leuven 1996ff. (up to now twelve volumes: Q 4, 1–13 , Q 6, 20–21 , Q 6, 37–42 , Q 7, 1–10 , Q 11, 2b–4 , Q 11, 39–44 , Q 11, 46–52 , Q 12, 8–12 , Q 12, 33–34 , Q 12, 49–59 , Q 13, 34–35 , Q 22, 28.30 ), ISBN 978-90-429-3053-7
- James M. Robinson, Paul Hoffmann, John S. Kloppenborg (Eds.): The Critical Edition of Q. Synopsis Including the Gospels of Matthew and Luke, Mark and Thomas with English, German, and French Translations of Q and Thomas. Managing Editor: Milton C. Moreland. Peeters Press, Leuven 2000, ISBN 978-90-429-0926-7 / Fortress Press, Minneapolis 2000, ISBN 978-0-8006-3149-9
- James M. Robinson, Paul Hoffmann, John S. Kloppenborg (Eds.): The Sayings Gospel Q in Greek and English with Parallels from the Gospels of Mark and Thomas. Managing Editor: Milton C. Moreland. Peeters Press, Leuven 2001, ISBN 978-90-429-1056-0 / Fortress Press, Minneapolis 2002, ISBN 978-0-8006-3494-0
- James M. Robinson (Ed.): The Sayings of Jesus: The Sayings Gospel Q in English. Fortress Press, Minneapolis 2002, ISBN 978-0-8006-3451-3
- Text and on-line resources for the Lost Sayings Gospel Q
- Internationales Q-Projekt
- The New Testament Gateway: Synoptic Problem Web Sites
- Q Web Materials
- Herbermann, Charles, ed. (1913). Catholic Encyclopedia. New York: Robert Appleton Company. .