derasha, in Judaism, a homily or sermon, generally preached by a rabbi in the synagogue.
In a broad sense, the prophets were the first to preach to the Jewish people, but they had no official status as interpreters of the Law, nor did they address their words to a formal congregation. The first derashot, properly so called, were preached by Ezra (5th century bc), who sensed the usefulness of following the reading of the Torah texts with a vernacular explanation for the common people. Long before the Christian era, such discourses became an integral part of the Jewish liturgy. In form and content, the derashot gradually changed with changing times. Some preachers provided didactic explanations of the Law, while others had recourse to allegory, parable, anecdote, or folklore.
Derashot were used by rabbis for the inspiration, encouragement, and sometimes the admonition of their congregations. Many early derashot from this era have been preserved in nonlegal sections of the Talmud and constitute a large portion of the Midrash (collected explanations of the underlying meaning of biblical texts). Derashot could serve as vehicles for social criticism and reform or as entertaining and instructive demonstrations of a rabbi’s eloquence and learning. Ethical teachings, however, remained the basis of the derasha.
Modern derashot continue to be flexible in form and content, but their reliance on ancient sources and traditions gives them a distinctive Jewish flavour. A typical derasha remains a speech of exhortation and instruction based on a particular text from the Scriptures.