Deuteronomy 27:1-8

1 Then Moses and the responsible men of Israel gave the people these orders: Keep all the orders which I have given you this day;
2 And on the day when you go over Jordan into the land which the Lord your God is giving you, put up great stones, coating them with building-paste,
3 And writing on them all the words of this law, after you have gone over; so that you may take the heritage which the Lord your God is giving you, a land flowing with milk and honey, as the Lord, the God of your fathers, has said.
4 And when you have gone over Jordan, you are to put up these stones, as I have said to you today, in Mount Ebal, and have them coated with building-paste.
5 There you are to make an altar to the Lord your God, of stones on which no iron instrument has been used.
6 You are to make the altar of the Lord your God of uncut stones; offering on it burned offerings to the Lord your God:
7 And you are to make your peace-offerings, feasting there with joy before the Lord your God.
8 And put on the stones all the words of this law, writing them very clearly.