Leviticus 23:10-12

10Speak unto the children of Israel and say unto them, When ye come into the land that I give unto you, and ye reap the harvest thereof, then ye shall bring a 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 next day after the sabbath the priest shall wave it.

12And ye shall offer that day when ye wave the sheaf, a he-lamb without blemish, a yearling, for a burnt-offering to Jehovah;