Isaac ben Eliezer Halevi
Rabbi Isaac ben Eliezer Halevi (Hebrew: רבי יצחק בן אליעזר הלוי; d. 1070) also known as Rabbi Isaac Segan Lewiyah (Hebrew: רבי יצחק סגן לויה) was an 11th-century French Talmudist, liturgical poet and Tosafist who flourished in Germany.
Born in Lorraine, France in his early years he studied under Gershom ben Judah, later moving to Worms where he served as the city's Chief Rabbi. He was an important teacher of Rashi, whom he was apparently related to. Rashi mentions him in his commentary on the Talmud and twice in his commentary on the Bible. He was the author of four wedding piyyutim, known as "Yotzer", "Ofan," "Zulat," and "Reshut". Abraham Zacuto states that he died in 1070 while Zunz states that he died between 1070 and 1096. 
- "Sefer Ha-Pardes," p. 35a; "Sefer Asufot," p. 150a
- "Teshuvot Maharshal 29:1". www.sefaria.org. Retrieved 2020-06-17.
- Rash mentions him in Yoma 39a; Sukkah 35b; Megillah. 26a
- Rash mentions him in 1 Sam.1:24 and Prov.19:24
- Zakut, Avraham ben Shemuel (1857). Sefer Yuḥasin ha-shalem (in Hebrew). Filipowski. p. 217.
- Zunz, Leopold, 1794-1886. (1966). Literaturgeschichte der synagogalen Poesie. Gg. Olms. p. 155. OCLC 1984522.CS1 maint: multiple names: authors list (link)
- "ISAAC BEN ELEAZAR HA-LEVI - JewishEncyclopedia.com". www.jewishencyclopedia.com. Retrieved 2020-06-17.
- For the partial collection of Rabbi Yitzchak Ben Eliezer Halevi's scanned manuscripts, see the Ketiv website - The National Library of Israel