Leviticus 23:5-11

5The Passover to the LORD begins at twilight on the fourteenth1 day of the first month. 6On the fifteenth day of the same month begins the Feast of Unleavened Bread2 to the LORD. For seven days you must eat unleavened bread. 7On the first day you are to hold a sacred assembly; you are not to do any regular work. 8For seven days you are to present a food offering to the LORD. On the seventh day there shall be a sacred assembly; you must not do any regular work.’”

9And the LORD said to Moses, 10“Speak to the Israelites and say, ‘When you enter the land that I am giving you and you reap its harvest, you are to bring to the priest a sheaf of the firstfruits of your harvest. 11And he shall wave the sheaf before the LORD so that it may be accepted on your behalf; the priest is to wave it on the day after the Sabbath.