Exodus 20:24-26

You shall make an altar of earth for Me, and sacrifice on it your burnt offerings and your peace offerings, your sheep and your oxen. In every place where I cause My Name to be recorded and remembered [through revelation of My divine nature] I will come to you and bless you. If you make an altar of stone for Me, you shall not build it of cut stones, for if you use a chisel on it, you will profane it. Nor shall you go up to My altar on steps, so that your nakedness will not be exposed on it.’