Leviticus 23:10-12

10“Give the following instructions to the people of Israel. When you enter the land I am giving you and you harvest its first crops, bring the priest a bundle of grain from the first cutting of your grain harvest.

11On the day after the Sabbath, the priest will lift it up before the Lord so it may be accepted on your behalf.

12On that same day you must sacrifice a one-year-old male lamb with no defects as a burnt offering to the Lord.