Leviticus 23:6-8

Thomson(i) 6 And on the fifteenth day of this month beginneth the festival of unleavened bread for the Lord. Seven days you shall eat unleavened bread. 7 Now the first day shall be a holy, set day for you. You shall do no sacrificial service, 8 but offer whole burnt offerings to the Lord seven days, and the seventh day shall be a holy set day for you. You shall do no sacrificial service.