Leviticus 23:37-38

37These are the rules for the special days of the Lord. You must tell people that they must bring offerings to the Lord on these days. They will bring gifts for burnt offerings each day. They must bring offerings of grain, animals and wine.

38These are not the usual Sabbath gifts to the Lord. They are not gifts to give thanks or for promises to the Lord. But they are extra gifts for special days.