Exodus 20:24,25
An altar of earth you shall make to me, and shall sacrifice thereon your burnt offerings, and your peace offerings, your sheep, and your oxen: in all places where I record my name I will come to you, and I will bless you.
Torrey's Topical Textbook—AKJV

Deuteronomy 27:5,6
And there shall you build an altar to the LORD your God, an altar of stones: you shall not lift up any iron tool on them.
Torrey's Topical Textbook—AKJV