Deuteronomy 26:2-4

2you must take the first of all the ground’s produce you harvest from the land the Lord your God is giving you, place it in a basket, and go to the place where he chooses to locate his name.

3You must go to the priest in office at that time and say to him, “I declare today to the Lord your God that I have come into the land that the Lord promised to our ancestors to give us.”

4The priest will then take the basket from you and set it before the altar of the Lord your God.