Exodus 20:25

tool The word (ḥéreb) commonly rendered -sword," occasionally used of other sharp instruments, Joshua 5:2-3 (-knives"): in Deuteronomy 27:5 E (Joshua 8:31) the word is replaced by -iron." Cf. 1Ma 4:47. The prohibition may be a survival either from a time when instruments of iron were not in general use, or from the time when the altar was a natural rock or boulder (cf. on v.24), supposed to be the abode of numenor deity, and it was imagined that to alter its shape would have the effect of driving the numenfrom it (Nowack, Arch.ii. 17; DB.i. 76 a, EB.i. 124). But naturally this is not the belief which actuates the prohibition here. An altar of stones, seemingly unhewn, was built by Elijah (1 Kings 18:32).

it(twice)] The pron. (which is fem. in the Heb.) refers not to -altar but to -stone": it is the stonewhich is profaned by being worked with a tool.