The tallit (Hebrew: טַלִּית), also calle tallis (Yiddish, plural taleysm), is a prayer shawl that is worn during the morning Jewish services (the Shacharit prayers) in Judaism, during the Torah service, and on Yom Kippur and other holidays. It has special twined and knotted fringes known as tzitzit attached to its four corners. The tallit is sometimes also referred to as the arba kanfot, meaning "four corners," although this term is more commonly used to refer only to the tallit katan undergarment with tzitzit. The bible mandates that the tzitzit contain a thread of blue known as tekhelet. Since the bible itself does not describe how to tie the tzitzit, interpretation of the oral tradition has resulted in a number of methods of tying.