After you've slain the beasts, Build an Altar

Deuteronomy 27:5-7

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

6 Thou shalt build the altar of the Lord thy God of whole stones: and thou shalt offer burnt offerings thereon unto the Lord thy God:

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