Deuteronomy 27:4-7

4Therefore it shall be when ye have gone over Jordan, that ye shall set up these stones, which I command you this day, in mount Ebal, and thou shalt plaster them with plaster.

5And there shalt thou build an altar to the LORD thy God, an altar of stones: thou shalt not lift up any iron tool upon them.

6Thou shalt build the altar of the LORD thy God of whole stones: and thou shalt offer on it burnt offerings to the LORD thy God:

7And thou shalt offer peace offerings, and shalt eat there, and rejoice before the LORD thy God.