Deuteronomy 27:5-10

5There also you will build an altar to Adonai your God, an altar of stones—you are not to use an iron tool on them.

6You are to build the altar of Adonai your God of whole stones, and you are to offer up burnt offerings on it to Adonai your God.

7You are to sacrifice fellowship offerings and eat there, and you will rejoice before Adonai your God.

8You are to write on the stones all the words of this Torah very clearly.”

9Then Moses and the Levitical kohanim spoke to all Israel, saying, “Be silent and listen, O Israel—this day you have become a people for Adonai your God.

10Therefore listen to the voice of Adonai your God, and do His mitzvot and statutes that I am commanding you today.”