Deuteronomy 16:16-17

All your men must appear before GOD, your God, three times each year at the place he designates: at the Feast-of-Unraised-Bread (Passover), at the Feast-of-Weeks, and at the Feast-of-Booths. No one is to show up in the Presence of GOD empty-handed; each man must bring as much as he can manage, giving generously in response to the blessings of GOD, your God. * * *