The feast of weeks, i.e. of pentecost, Acts 2:1. Which thou shalt give, over and besides what was appointed, Leviticus 23:17-20 Numbers 28:27-31.
Related Commentaries of Deuteronomy 16:10
Deuteronomy 16:10
10 And thou shalt keep the feast of weeks unto the LORD thy God with a tributeb of a freewill offering of thine hand, which thou shalt give unto the LORD thy God, according as the LORD thy God hath blessed thee: