Deuteronomy 27:4-6

New International Version

⁴ And when you have crossed the Jordan, set up these stones on Mount Ebal,^(A) as I command you today, and coat them with plaster. ⁵ Build there an altar^(B) to the Lord your God, an altar of stones. Do not use any iron tool^(C) on them. ⁶ Build the altar of the Lord your God with fieldstones and offer burnt offerings on it to the Lord your God.