YEẒIRAH, SEFER The Power of the Name. The title of two esoteric books. Of these the older is also called "Hilkot Yeẓirah" (Rules of Creation), and is a thaumaturgical work that was popular in the Talmudic period. "On the eve of every Sabbath,
YIBBUM See Levirate Marriage.
YIGDAL The hymn which in the various rituals shares with Adon 'Olam the place of honor at the opening of the morning and the close of the evening service. It is based on the thirteen Articles of Faith (usually called the Thirteen