Leviticus 23:5-11

5In the fourteenth day of the first month at even is Yhwh's passover. 6And on the fifteenth day of the same month is the feast of unleavened bread unto Yhwh: seven days ye must eat unleavened bread. 7In the first day ye shall have an holy convocation: ye shall do no servile work therein. 8But ye shall offer an offering made by fire unto Yhwh seven days: in the seventh day is an holy convocation: ye shall do no servile work therein.

9And Yhwh spake unto Moses, saying, 10Speak 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:1 11And he shall wave the sheaf before Yhwh, to be accepted for you: on the morrow after the sabbath the priest shall wave it.