Johan Christian Jacob Kemper (1670–1716), formerly Moshe ben Aharon of Kraków, was a Polish Sabbatean Jew who converted from Judaism to Lutheran Christianity. His conversion was motivated by his studies in Kabbalah and his disappointment following the failure of a prophecy spread by the Polish Sabbatean prophet Tzadok of Gordno, which predicted that Sabbatai Zevi would return in the year 1695/6, It is unclear whether he continued to observe Jewish practices after his conversion.
During his time at Uppsala, he wrote his three-volume work on the Zohar entitled Matteh Moshe (The Staff of Moses), (1711). In it, he attempted to show that the Zohar contained the Christian doctrine of the Trinity.
This belief also drove him to make a literal Hebrew translation of the Gospel of Matthew from Syriac (1703). He also wrote Me'irat 'Enayim (The Enlightenment of the Eyes), (1704) a Christian Cabala commentary on Matthew, which emphasized the unity of the Old and New Testaments and used elements from the Sabbatean and non-Sabbatean Kabbalistic traditions to derive Christian beliefs and meanings from traditional Jewish beliefs and practices.
In his commentary on polemical treatment of Christianity in rabbinical literature he was one of the first Lutherans to comment on the connection between the form of the name "Joshua" used for Jesus in the Talmud, Yeshu instead of the normal Yeshua used for other figures, and connected the dropping of the final ayin with the ancient curse yimakh shemo.
After his death, Kemper's student Andreas Norrelius (1679–1749) translated the commentary into Latin as Illuminatio oculorum (The Light of the Eyes),(1749).
- Hebrew Translation of Matthew's Gospel, (1703)
- Meriat Enayim, (1704)
- Matteh Moshe, (1711)
- Wolfson, Elliot R. "Messianism in the Christian Kabbala of Johann Kemper", The Journal of Scriptural Reasoning, Volume 1, No. 1, August 2001 (also appears in Goldish et al. (2001))
- Dole, George, F. "Philosemitism in the Seventeenth Century",Studia Swedenborgiana, Volume 7, No. 1, December 1990
- Eskhult, M. "Rabbi Kemper's Case for Christianity in his Matthew Commentary, with Reference to Exegesis" in T. L. Hettema, Arie van der Kooij. Religious Polemics in Context: Papers Presented to the Second International Conference of the Leiden Institute for the Study of Religions (Lisor) Held at Leiden, 27–28 April 2000. Uitgeverij Van Gorcum, 2004. ISBN 90-232-4133-9
- Schoeps, Hans-Joachim, trans. Dole, George F., Barocke Juden, Christen, Judenchristen, Bern: Francke Verlag, 1965, pp. 60-67
- KABBALAH? CABALA? QABALAH? from Jewish kabbalaonline.org
- Mats Eskhult Rabbi Kemper's Case for Christianity in His Matthew Commentary, with Reference to Exegesis (per Mats Eskhult (Uppsala University) Hebrew Studies within Seventeenth Century Swedish Lutheranism) in Religious polemics in context: papers presented to the Second International Conference of the Leiden Institute for the Study of Religions (LISOR) ed. Theo L. Hettema, Arie van der Kooij - Page 161 2004 - "This is applied to Jesus: "It is easy to see that Jesus is spoken of," Kemper says, "and still today they mock him by rendering his name without 'ayin as Yeshu, ie, yimmah stud wezikro 'may his name and memory be wiped out."
- Eskhult, Josef (ed.), Andreas Norrelius' Latin translation of Johan Kemper's Hebrew commentary on Matthew: edited with introduction and philological commentary by Josef Eskhult Uppsala,2007. ISBN 978-91-554-7050-0
- Goldish, M. Kottman, K.A. Popkin, R.H. Force, J.E. Laursen, J.C. (eds.), Millenarianism and Messianism in Early Modern European Culture: From Savonarola to the Abbé Grégoire. Springer, 2001. ISBN 0-7923-6850-9
- Maciejko, P. "Mosheh Ben Aharon Ha-Kohen of Krakow," in Hundert, G.D. (ed.), The YIVO Encyclopedia of Jews in Eastern Europe,. Yale, 2008. ISBN 0-300-11903-8
- Shifra, A. "Another Glance at Sabbatianism, Conversion, and Hebraism in Seventeenth Century Europe: Scrutinizing the Character of Johan Kempper (sic) of Uppsala, or Moshe Son of Aharon of Krakow," in Elior, R. (ed.), The Sabbatian Movement and Its Aftermath: Messianism, Sabbatianism and Frankism,(Hebrew), Hebrew University. Jerusalem.
- Wolfson, E. “Messianism in the Christian Kabbalah of Johann Kemper,” in Millenarianism and Messianism in the Early Modern European Culture: Jewish Messianism in the Early Modern World, 139-187. Edited by M. D. Goldish and R. H. Popkin. The Netherlands: Kluwer Academic Publishers, 2001
- Wolfson, E. “Angelic Embodiment and the Feminine Representation of Jesus: Reconstructing Carnality in the Christian Kabbalah of Johann Kemper,” in The “Jewish Body” in the Early Modern Period, 395-426'. Edited by M. Diemling and G. Veltri. Leiden: Brill, 2008