Deuteronomy 16:10
And thou shalt keep the feast of weeks unto the LORD thy God with a tribute 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:And thou shalt keep the feast of weeks unto the LORD thy God with a tribute 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: