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.