Leviticus 23:8

5 In the fourteenth day of the first month at even is the LORD'S passover.

6 And on the fifteenth day of the same month is the feast of unleavened bread unto the LORD: seven days ye must eat unleavened bread.

7 In the first day ye shall have an holy convocation: ye shall do no servile work therein.

8 But ye shall offer an offering made by fire unto the LORD seven days: in the seventh day is an holy convocation: ye shall do no servile work therein.

9 And the LORD spake unto Moses, saying,

10 Speak unto the children of Israel, and say unto them, When ye be come into the land which I give unto you, and shall reap the harvest thereof, then ye shall bring a sheaf of the firstfruits of your harvest unto the priest:

11 And he shall wave the sheaf before the LORD, to be accepted for you: on the morrow after the sabbath the priest shall wave it.