Bible Verses About Altars: To be made of earth, or unhewn stone

You are to make for Me an altar of earth, and sacrifice on it your burnt offerings and peace offerings, your sheep and goats and cattle. In every place where I cause My name to be remembered, I will come to you and bless you.

Now if you make an altar of stones for Me, you must not build it with stones shaped by tools; for if you use a chisel on it, you will defile it.

Moreover, you are to build there an altar to the LORD your God, an altar of stones. You must not use any iron tool on them.

You shall build the altar of the LORD your God with uncut stones and offer upon it burnt offerings to the LORD your God.