Leviticus 23:10-12

10“Speak to the sons of Israel and say to them, ‘When you enter the land which I am going to give to you and you 1gather its harvest, then you shall bring in the sheaf of the first fruits of your harvest to the priest.

11He shall wave the sheaf before the Lord for you to be accepted; on the day after the Sabbath the priest shall wave it.

12Now on the day when you wave the sheaf, you shall offer a male lamb one year old without defect as a burnt offering to the Lord.