Ashkenaz is a Hebrew word for Germany, and in particular to the area along the Rhine where the allemani tribe once lived (compare the French word Allemand for Germany).
The word ashkenazi is often used in medieval rabbinic literature. References to Ashkenaz in Yosippon and Hasdai's letter to the king of the Khazars would date the term as far back as the tenth century, as would also Saadia Gaon's commentary on Daniel 7:8. Literature about the alleged Turkic origin of the Ashkenazi population appeared mainly after 1950. In the first half of the eleventh century Hai Gaon refers to questions that had been addressed to him from Ashkenaz, by which he undoubtedly means Germany. Rashi in the latter half of the eleventh century refers to both the language of Ashkenaz (Commentary on Deut. iii. 9; idem on Talmud tractate Suk. 17a) and the country of Ashkenaz (Talmud, Hul. 93a). During the twelfth century the word appears quite frequently. In the "Mahzor Vitry", the kingdom of Ashkenaz is referred to chiefly in regard to the ritual of the synagogue there, but occasionally also with regard to certain other observances (ib. p. 129).
In the literature of the thirteenth century references to the land and the language of Ashkenaz often occur. See especially Solomon ben Adret's Responsa (vol. i., No. 395); the Responsa of Asher ben Jehiel (pp. 4, 6); his "Halakot" (Berakot i. 12, ed. Wilna, p. 10); the work of his son Jacob ben Asher, "Tur Orah Hayyim" (lix.); the Responsa of Isaac ben Sheshet (Nos. 193, 268, 270).
The first use of the name comes from a midrash about the descendants of Japheth (Genesis 10.1.) In the midrash compilation Genesis Rabbah, Rabbi Berechiah mentions "Ashkenaz, Riphath, and Togarmah" as German tribes or as German lands. It may correspond to a Greek word that may have existed in the Greek dialect of the Palestinian Jews, or the text is corrupted from "Germanica." This view of Berechiah is based on the Talmud (Yoma 10a; Yer. Meg. 71b), where Gomer, the father of Ashkenaz, is translated by "Germamia," which evidently stands for Germany, and which was suggested by the similarity of the sound.
In later times the word Ashkenaz is used to designate southern and western Germany, the ritual of which sections differs somewhat from that of eastern Germany and Poland. Thus the prayer-book of Isaiah Horowitz, and many others, give the piyyutim according to the Minhag of Ashkenaz and Poland.
During Passover, Ashkenazic Jews traditionally refrain from eating legumes, peanuts, corn, millet, and rice, whereas Sephardic Jews do not prohibit themselves from consuming these foods.
Ashkenazic Jews frequently name newborn children after deceased family members, but not after living relatives. Sephardic Jews, on the other hand, often name their children after living relatives.
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The term Ashkenazi also refers to the nusach (Hebrew, "liturgical tradition") used by Ashkenazi Jews in their Siddur (prayer book). A nusach is defined by a liturgical tradition's choice of prayers, order of prayers, text of prayers and melodies used in the singing of prayers.
This phrase is often used in contrast with Sephardic Jews, also called Sephardim, who are descendants of Jews from Spain, Portugal and North Africa. There are some differences in how the two groups pronounce Hebrew, and in points of ritual.
Several famous people have this as a surname, e.g. Vladimir Ashkenazi. History of the word Ashkenaz
Customs, laws and traditions
Relationship to other Jews