Leviticus 23:33-36

33The Lord said to Moses, 34“Say to the Israelites: ‘On the fifteenth day of the seventh month the Lord’s Festival of Tabernacles begins, and it lasts for seven days. 35The first day is a sacred assembly; do no regular work. 36For seven days present food offerings to the Lord, and on the eighth day hold a sacred assembly and present a food offering to the Lord. It is the closing special assembly; do no regular work.