Leviticus 23:13

“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.

You must not eat bread, or roasted grain, or fresh grain, until this same day, until you have brought the offering of your God. This is a statute forever throughout your generations in all your dwellings.

“‘You shall count from the next day after the Sabbath, from the day that you brought the sheaf of the wave offering: seven Sabbaths shall be completed.

The next day after the seventh Sabbath you shall count fifty days; and you shall offer a new meal offering to the LORD.