Rashi

Rabbi Shlomo Yitzchaki of Troyes — known everywhere by the acronym Rashi — is the preeminent commentator of Judaism and the starting point of nearly all later Jewish reading of the Bible and Talmud. Writing in eleventh-century Champagne, he produced a running commentary on almost the whole Hebrew Bible and a comprehensive commentary on the Talmud, both marked by extraordinary concision and clarity. To this day his words are printed alongside the text in virtually every traditional edition, and no student of either work goes far without him.