Hallelujah (// HAL-i-LOO-yə; Hebrew: הַלְלוּ-יָהּ haləlū-Yāh) is an interjection used as an expression of gratitude and adoration. The term is used 24 times in the Hebrew Bible (in the book of Psalms), twice in deuterocanonical books, and four times in the Christian Book of Revelation.
The phrase is used in Judaism as part of the Hallel prayers, and in Christian prayer, where since the earliest times it is used in various ways in liturgies, especially those of the Catholic Church and the Eastern Orthodox Church, both of which use the form "alleluia" which is based on the alternative Greek transliteration.
Hallelujah is a transliteration of the Hebrew phrase הַלְלוּ יָהּ (halelū yāh), which means "praise ye Jah!" (from הַלְלוּ, "praise ye!"  and יָהּ, "Jah".) The word hallel in Hebrew means a joyous praise in song. The second part, Yah, is a shortened form of YHWH (Yahweh or Jehovah in modern English).
In the Hebrew Bible hallelujah is actually a two-word phrase, halelu-Yah, and not one word. The first part, halelu, is the second-person imperative masculine plural form of the Hebrew verb hillel. However, "hallelujah" means more than simply "praise Jah" or "praise Yah", as the word halel in Hebrew means a joyous praise in song, to boast in God.
The second part, Yah, is a shortened form of YHWH, the name of the national god of Israel. The name ceased to be pronounced in Second Temple Judaism, by the 3rd century BC due to religious beliefs. The correct pronunciation is not known, however, it is sometimes rendered as "Yahweh" or "Jehovah". The Septuagint translates Yah as Kyrios (the LORD), because of the Jewish custom of replacing the sacred name with "Adonai", meaning "my Lord".
In Psalm 150:6 the Hebrew reads kol han'shamah t'halel yah halelu-yah; the first "hallel" and "yah" in this verse are two separate words, and the word "yah" is translated as "the LORD", or "YHWH". In 148:1 the Hebrew says halelu yah halelu eth-YHWH, notably including both the shortened Yah and the full name of YHWH.
Most well-known English versions of the Hebrew Bible translate the Hebrew "Hallelujah" (as at Psalm 150:1) as "Praise the LORD", though "LORD" is instead translated as "Yah" in the Lexham English Bible and Young's Literal Translation, "Jah" in the New World Translation, "Jehovah" in the American Standard Version, and "HaShem" in the Artscroll Tanach (Orthodox Jewish). Rather than directly translating it, the JPS Tanakh, International Standard Version, Darby Translation, God's Word Translation, Holman Christian Standard Bible, and The Message render the term as "Hallelujah", with the spelling "Halleluyah" appearing in the Complete Jewish Bible. The Greek-influenced form "Alleluia" appears in Wycliffe's Bible, the Knox Version and the New Jerusalem Bible.
In the great song of praise to God for his triumph over the Whore of Babylon in chapter 19 of the New Testament book of Revelation, the Greek word ἀλληλούϊα (allēluia), a transliteration of the same Hebrew word, appears four times, as an expression of praise rather than an exhortation to praise. In English translations this is mostly rendered as "Hallelujah", but as "Alleluia" in several translations, while a few have "Praise the Lord", "Praise God", "Praise our God", or "Thanks to our God".
The linguist Ghil'ad Zuckermann argues that the word Hallelujah is usually not replaced by a praise God! translation due to the belief in iconicity: the perception that there is something intrinsic about the relationship between the sound of the word and its meaning.: 62
In the Bible
The Greek transliteration ἀλληλούϊα (allēlouia) appears in the Septuagint version of these Psalms, in Tobit 13:17 and 3 Maccabees 7:13, and four times in Revelation 19:1–6, the great song of praise to God for his triumph over the Whore of Babylon. It is this usage that Charles Jennens extracted for the Hallelujah Chorus in Handel's Messiah. This transliteration is the basis of the alternative English transliteration "Alleluia" that is also used by Christians.
Usage by Jews
The word "hallelujah" is sung as part of the Hallel Psalms (interspersed between Psalms 113–150). In Tractate Shabbat of the Talmud, Rabbi Yose is quoted as saying that the Pesukei dezimra Psalms should be recited daily. Psalms 145–150, also known as the Hallel of pesukei dezimra, are included to fulfill this requirement in the liturgy for the traditional Jewish Shacharit (morning) service. In addition, on the three Pilgrimage Festivals, the new moon and Hanukkah, Psalms 113-118 are recited. The latter psalms are known simply as Hallel with no additional qualification.
Psalms 146:10, ending with Halleluja, is the third and final biblical quotation in the Kedushah. This expanded version of the third blessing in the Amidah is said during the Shacharit and Mincha (morning and afternoon) services when there is a minyan present.
Usage by Christians
For most Christians, "Hallelujah" is considered a joyful word of praise to God, rather than an injunction to praise him. "The Alleluia" refers to a traditional chant, combining the word with verses from the Psalms or other scripture. In the Latin Rite of the Catholic Church, and in many older Protestant denominations, the Alleluia, along with the Gloria in excelsis Deo, is not spoken or sung in liturgy during the season of Lent, instead being replaced by a Lenten acclamation, while in Eastern Churches, Alleluia is chanted throughout Lent at the beginning of the Matins service, replacing the Theos Kyrios, which is considered more joyful. At the Easter service and throughout the Pentecostarion, Christos anesti is used in the place where Hallelujah is chanted in the western rite expressing happiness.
In contemporary worship among many Protestants, expressions of "Hallelujah" and "Praise the Lord" are acceptable spontaneous expressions of joy, thanksgiving and praise towards God, requiring no specific prompting or call or direction from those leading times of praise and singing.
Usage in informal language
- Alhamdulillah (ٱلْحَمْدُ لِلَّٰهِ), similar Arabic phrase used by Muslims and by Arabic-speaking Jews and Christians
- Allah Akbar (ٱللَّٰهُ أَكْبَرُ), similar Arabic phrase
- Alleluia, liturgical chant
- Subhan Allah (سُبْحَانَ ٱللَّٰهِ), similar Arabic phrase
- My Sweet Lord, a 1970 song by George Harrison which includes hallelujah along with Hare Krishna.
- Woods, F. H. (1902). "Hallelujah". In James Hastings (ed.). A Dictionary of the Bible. New York: Charles Scribner's Sons. p. 287.
- Scott Nash, "Hallelujah" in Mercer Dictionary of the Bible (Mercer University Press 1990 ISBN 978-0-86554373-7), p. 355
- Alter, Robert (2007). The Book of Psalms: A Translation with Commentary. W. W. Norton & Company. ISBN 978-0-393-06226-7.
- Andrew McGowan, "Alleluia" in The New Scm Dictionary of Liturgy and Worship (Hymns Ancient & Modern 2002 ISBN 978-0-33402883-3), p. 6
- Page H. Kelley, Biblical Hebrew, an Introductory Grammar, page 169. Ethics & Public Policy Center, 1959. ISBN 978-0-8028-0598-0.
- Hallelujah, also spelled Alleluia, Encyclopædia Britannica
- Brown-Driver-Briggs (Hebrew and English Lexicon, page 238)
- page 403, note on line 1 of Psalm 113, Alter, Robert (2007). The Book of Psalms: A Translation with Commentary. W. W. Norton & Company. ISBN 978-0-393-06226-7.
- George Fohrer. Hebrew and Aramaic Dictionary of the Old Testament, under הלל. Walter de Gruyter, 1973. ISBN 978-3-11-004572-7.
- Joseph Samuel C.F. Frey, A Hebrew, Latin, and English dictionary, 1815, entry for הלל on page 254
- Harris, Stephen L. Understanding the Bible: a reader's introduction, 2nd ed. Palo Alto: Mayfield. 1985. page 21.
- All quotes from the Hebrew are taken from Biblia Hebraica Stuttgartensia, EDITIO FUNDITUS RENOVATA, cooperantibus H. P. Ruger et J. Ziegler ediderunt K. Elliger et W. Rudolph, Textum Masoreticum curavit H. P. Ruger MASORAM ELABORAVIT G. E. WEIL, Editio quinta emendata opera A. Schenker, Deutsche Bibelgesellschaft.
- Variants of "Hallelujah" in this context are "Hallelujah (praise the Lord)" in the Amplified Bible and "Halleluyah" in Complete Jewish Bible
- King James Version and its recent revisions, the 21st Century King James Version and the New King James Version, the Douay-Rheims Bible, the Knox Version, the New Jerusalem Bible, the Phillips New Testament, Wycliffe's Bible, and Young's Literal Translation.
- Contemporary English Version, New Living Translation (LORD)
- Good News Translation
- Worldwide English (New Testament)
- New Life Version
- Zuckermann, Ghil'ad (2003), Language Contact and Lexical Enrichment in Israeli Hebrew. Palgrave Macmillan. ISBN 9781403917232 / ISBN 9781403938695 
- Psalm 104:35; 105:45; 106:1, 48; 111:1; 112:1; 113:1, 9; 115:18; 116:19; 117:2; 135:1, 3, 21; 146:1, 10; 147:1, 20; 148:1, 14; 149:1, 9; 150:1, 6.
- David E. Garland, Psalms, Volume 5 of The Expositor's Bible Commentary, page 62.
- Shabbat 118b, Sefaria
- Scott-Martin Kosofsky, The Book of Customs, Harper San Francisco, 2004; pages 25-26.
- Elie Munk, The World of Prayer, Vol. 2, Revised ed., Feldheim, Jerusalem, 2007; pages 129-133.
- Scott-Martin Kosofsky, The Book of Customs, Harper San Francisco, 2004; page 33.
- At Pipe Organ Pizza, a pipeline for prayers, Milwaukee Journal, July 12, 1981
- Hallelujah definition in Macmillan Dictionary
- The dictionary definition of hallelujah at Wiktionary