Deuteronomy 27:6

6 because any altar you build for the Lord your God must be made of uncut stones. There you are to offer the sacrifices that are to be burned,

Deuteronomy 27:6 Meaning and Commentary

Deuteronomy 27:6

Thou shall build the altar of the Lord thy God of whole
stones
And of such Joshua did build it, ( Joshua 8:31 ) ;

and thou shalt offer burnt offerings thereon unto the Lord thy God;
and very likely sin offerings too; for these frequently went together, the one to make atonement for sin, and the other as a gift, and by way of thankfulness for the acceptance of the former; and both typical of Christ, the true sacrifice, and the antitype of all the legal sacrifices.

Deuteronomy 27:6 In-Context

4 and you are on the other side of the Jordan, set up these stones on Mount Ebal, as I am instructing you today, and cover them with plaster.

5 Build an altar there made of stones that have had no iron tools used on them,

6 because any altar you build for the Lord your God must be made of uncut stones. There you are to offer the sacrifices that are to be burned,

7 and there you are to sacrifice and eat your fellowship offerings and be grateful in the presence of the Lord your God.

8 On the stones covered with plaster write clearly every word of God's laws."