Leviticus 23:9-11

And Jehovah spake unto Moses, saying, Speak 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: and he shall wave the sheaf before Jehovah, to be accepted for you: on the morrow after the sabbath the priest shall wave it.