Deuteronomy 27:5–7

5 And there you shall build an altar to the Lord your God, an altar of stones. wYou shall wield no iron tool on them; 6 you shall build an altar to the Lord your God of uncut1 stones. And you shall offer burnt offerings on it to the Lord your God, 7 and you shall sacrifice peace offerings and xshall eat there, and you xshall rejoice before the Lord your God.