Adon Olam (; "Lord of the World [of which He is King]") is one of the few strictly metrical hymns in the Jewish liturgy, the nobility of the diction of which and the smoothness of whose versification have given it unusual importance. According to the custom of the Sephardim and in British synagogues generally, it is congregationally sung at the close of the Sabbath and festival morning services, and among the Ashkenazim also it often takes the place of the hymn Yigdal at the close of the evening service on these occasions, while both hymns are almost universally chanted on the Eve of Atonement (Kol Nidre). Because of this solemn association, and on account of its opening and closing sentiments, the hymn has also been selected for reading in the chamber of the dying.