There you shall build: the important thing about Mount Ebal is the altar, not the stones.

An altar of stones … lift up no iron tool on them: the altar is to be built with stones as they are found, without any work being done on them with iron tools to shape them. Another way to express this is “But don’t use stones that you have cut with iron tools.” For altar see 7.5.

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on Deuteronomy. (UBS Helps for Translators). New York: UBS, 2000. For this and other handbooks for translators see here .