Leviticus 23:5-11

5In the fourteenth day of the first month at evening is the LORD’S passover. 6And on the fifteenth day of the same month is the feast of unleavened bread to the LORD: seven days ye must eat unleavened bread. 7In the first day ye shall have an holy convocation: ye shall do no servile work in it. 8But ye shall offer an offering made by fire to the LORD seven days: in the seventh day is an holy convocation: ye shall do no servile work in it . 9And the LORD spoke to Moses, saying, 10Speak to the children of Israel, and say to them, When ye shall have come into the land which I give to you, and shall reap its harvest, then ye shall bring a sheaf of the firstfruits of your harvest to the priest:1 11And 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.