to which the Talmud owes its origin was established in Babylonia by Rav. That method takes the Mishnah of Judah haNasi as a text or foundation, adding to it the other tannaitic traditions, and deriving from all of them the theoretical explanations and practical applications of the religious Law. The legal and ritual opinions recorded in Rav's name and his disputes with Samuel constitute the main body of the Babylonian Talmud. His numerous disciples—some of whom were very influential and who, for the most part, were also disciples of Samuel—amplified and, in their capacity as instructors and by their discussions, continued the work of Rav. In the Babylonian schools, Rav was rightly referred to as "our great master." Rav also exercised a great influence for good upon the moral and religious conditions of his native land, not only indirectly through his disciples, but directly by reason of the strictness with which he repressed abuses in matters of marriage and divorce, and denounced ignorance and negligence in matters of ritual observance. Rav, says tradition, found an open, neglected field and fenced it in. Teachings He gave special attention to the liturgy of the synagogue. The Aleinu prayer first appeared in the manuscript of the Rosh Hashana liturgy by Rav. He included it in the Rosh Hashana mussaf service as a prologue to the Kingship portion of the Amidah. For that reason some attribute to Rav the authorship, or at least the revising, of Aleinu. In this noble prayer are evinced profound religious feeling and exalted thought, as well as ability to use the Hebrew language in a natural, expressive, and classical manner. The many homiletic and ethical sayings recorded of him show similar ability. The greatest aggadist among Babylonian Amoraim, he is the only one of them whose aggadic utterances approach in number and contents those of the Palestinian haggadists. The Jerusalem Talmud has preserved a large number of his halakhic and aggadic utterances; and the Palestinian Midrashim also contain many of his aggadot. Rav delivered homiletic discourses, both in the beit midrash and in the synagogues. He especially loved to discuss in his homilies the events and personages of Biblical history; and many beautiful and genuinely poetic embellishments of the Biblical record, which have become common possession of the aggadah, are his creations. His aggadah is particularly rich in thoughts concerning the moral life and the relations of human beings