Exodus 20:24-25 ▼

24 You make an altar of earth for Me, and you have sacrificed on it your burnt-offerings and your peace-offerings, your flock and your herd; in every place where I cause My Name to be remembered I come to you, and have blessed you.

25 And if you make an altar of stones for Me, you do not build them of hewn work; when you have waved your tool over it, then you defile it;