Leviticus 23:10-12

10“Speak to Bnei-Yisrael and tell them: When you have come into the land which I give to you, and reap its harvest, then you are to bring the omer of the firstfruits of your harvest to the kohen.

11He is to wave the omer before Adonai, to be accepted for you. On the morrow after the Shabbat, the kohen is to wave it.

12On the day when you wave the omer you are to offer a male lamb without blemish, one year old, as a burnt offering to Adonai.