Numbers 31:48

“And the officers which were over thousands of the host, etc.] Over the twelve thousand, of which the host or army consisted: namely, the captains of thousands, and the captains of hundreds, came near unto Moses; of their own accord, without being sent, or required to do what they did.”

“officers . . . said . . . there lacketh not one man of us--A victory so signal, and the glory of which was untarnished by the loss of a single Israelitish soldier, was an astonishing miracle. So clearly betokening the direct interposition of Heaven, it might well awaken the liveliest feelings of grateful acknowledgment to God (Psa 44:2-3). The oblation they brought for the Lord "was partly an atonement" or reparation for their error (Num 31:14-16), for it could not possess any expiatory virtue, and partly a tribute of gratitude for the stupendous service rendered them. It consisted of the "spoil," which, being the acquisition of individual valor, was not divided like the "prey," or…”

“31:48-49 Though it is unusual for no soldiers from an army to be killed in battle, it is not impossible. Classical authors also reported battles in which few or no Roman soldiers were killed. If the Israelites had the advantages of preparation, surprise, and overwhelming force, they could have defeated the Midianites and lost no troops, especially in light of God’s blessing.”

“Sacred Oblations of the Officers. - When the officers reviewed the men of war who were "in their hand," i.e., who had fought the battle under their command, and found not a single man missing, they felt constrained to give a practical expression to their gratitude for this miraculous preservation of the whole of the men, by presenting a sacrificial gift to Jehovah; they therefore brought all the golden articles that they had received as booty, and offered them to the Lord "for the expiation of their souls" (see at Lev 1:4), namely, with the feeling that they were not worthy of any such grace, and not "because they had done wrong in failing to destroy all the enemies of Jehovah" (Knobel).…”