Leviticus 23:9

On the fifteenth day of the same month is the feast of unleavened bread to the LORD. Seven days you shall eat unleavened bread.

In the first day you shall have a holy convocation. You shall do no regular work.

But you shall offer an offering made by fire to the LORD seven days. In the seventh day is a holy convocation. You shall do no regular work.’”

“Speak to the children of Israel, and tell them, ‘When you have come into the land which I give to you, and shall reap its harvest, then you shall bring the sheaf of the first fruits of your harvest to the priest.

He shall wave the sheaf before the LORD, to be accepted for you. On the next day after the Sabbath the priest shall wave it.

On the day when you wave the sheaf, you shall offer a male lamb without defect a year old for a burnt offering to the LORD.