Deuteronomy 16:8-10

Amplified Bible

⁸ For six days you shall eat unleavened bread, and on the seventh day there shall be a celebration to the Lord your God; so you shall do no work [on that day].

The Feast of Weeks

⁹ “You shall count seven weeks for yourself; you shall begin to count seven weeks from the time you first put the sickle to the standing grain. ¹⁰ Then you shall celebrate the ^[a]Feast of Weeks to the Lord your God with a tribute of a freewill offering from your hand, which you shall give [to Him] just as the Lord your God blesses you;