Then the Lord told Moses, "This is what you are to say to the Israelites: You have seen that I have spoken to you from heaven.
References for Exodus 20:22
You must not make gods of silver to rival Me; you must not make [gods of gold] for yourselves.
References for Exodus 20:23
"You must make an earthen altar for Me and sacrifice on it your burnt offerings and fellowship offerings, your sheep and goats, as well as your cattle. I will come to you and bless you in every place where I cause My name to be remembered.
If you make a stone altar for Me, you must not build it out of cut stones. If you use your chisel on it, you will defile it.
You must not go up to My altar on steps, so that your nakedness is not exposed on it.