Deuteronomy 27:3-7

and write on them all the words of this Law, when you cross over, so that you may enter the land which the Lord your God is giving you, a land flowing with milk and honey, just as the Lord, the God of your fathers, promised you.

So it shall be when you cross the Jordan, you shall set up these stones on Mount Ebal, as I am commanding you today, and you shall coat them with lime.

Moreover, you shall build there an altar to the Lord your God, an altar of stones; you shall not wield an iron tool on them.

You shall build the altar of the Lord your God of uncut stones, and you shall offer on it burnt offerings to the Lord your God;

and you shall sacrifice peace offerings and eat there, and rejoice before the Lord your God.