Deuteronomy 16:8-10 Modern English Version (MEV)
8 For six days you must eat unleavened bread, and on the seventh day there shall be a solemn assembly to the Lord your God. You must do no work on that day.
The Feast of Weeks
9 You must count seven weeks for yourself. Begin counting the seven weeks from the time you begin to put the sickle to the standing grain. 10 You must keep the Feast of Weeks to the Lord your God with a tribute of a freewill offering from your hand, which you must give to the Lord your God, in proportion to how much the Lord your God has blessed you.