Leviticus 23:10-12

10Speak unto the children of Israel, and say unto them, When ye are come into the land which I give unto you, and shall reap the harvest thereof, then ye shall bring the sheaf of the first-fruits of your harvest unto the priest: 11and he shall wave the sheaf before Jehovah, to be accepted for you: on the morrow after the sabbath the priest shall wave it. 12And in the day when ye wave the sheaf, ye shall offer a he-lamb without blemish a year old for a burnt-offering unto Jehovah.