Leviticus 23:8, 12, 36

But ye shall offer an offering made by fire unto the LORD seven days: in the seventh day is an holy convocation: ye shall do no servile work therein.

And ye shall offer that day when ye wave the sheaf an he lamb without blemish of the first year for a burnt offering unto the LORD.

Seven days ye shall offer an offering made by fire unto the LORD: on the eighth day shall be an holy convocation unto you; and ye shall offer an offering made by fire unto the LORD: it is a solemn assembly; and ye shall do no servile work therein.