Burn them with fire - Or, “kindle fire with them;” or, as in the margin. The weapons of the army left on the field of battle shall be so numerous as to supply fuel for the people of the land for seven years. Seven was a number connected with cleansing after contact with the dead (Numbers 19:11 ff), and this purification of the land by the clearance of paganish spoils was a holy work (compare Ezekiel 39:12).
Related Commentaries of Ezekiel 39:9
Ezekiel 39:9-10
9 And they that dwell in the cities of Israel shall go forth, and shall set on fire and burn the weapons, both the shields and the bucklers, the bows and the arrows, and the handstaves,d and the spears, and they shall burn them with fire seven years:
10 So that they shall take no wood out of the field, neither cut down any out of the forests; for they shall burn the weapons with fire: and they shall spoil those that spoiled them, and rob those that robbed them, saith the Lord GOD.