Leviticus 23:8, 12, 36

But you shall offer an offering made by fire to the LORD for seven days. The seventh day shall be a holy convocation; you shall do no customary work on it.’ ”

And you shall offer on that day, when you wave the sheaf, a male lamb of the first year, without blemish, as a burnt offering to the LORD.

For seven days you shall offer an offering made by fire to the LORD. On the eighth day you shall have a holy convocation, and you shall offer an offering made by fire to the LORD. It is a sacred assembly, and you shall do no customary work on it.