Exodus 20:22-26

22The Lord said to Moses: “Thus you will tell the Israelites: ‘You yourselves have seen that I have spoken with you from heaven.

23You must not make gods of silver alongside me, nor make gods of gold for yourselves.

24‘You must make for me an altar made of earth, and you will sacrifice on it your burnt offerings and your peace offerings, your sheep and your cattle. In every place where I cause my name to be honored I will come to you and I will bless you.

25If you make me an altar of stone, you must not build it of stones shaped with tools, for if you use your tool on it you have defiled it.

26And you must not go up by steps to my altar, so that your nakedness is not exposed.’