John Gill Commentary Numbers 31:49

"and they said unto Moses, Thy servants have taken the sum of the men of war that are under our charge, and there lacketh not one man of us." — Numbers 31:49 (ASV)

And they said to Moses Gave the following relation to him, which is a very surprising one: your servants have taken the sum of the men of war which are under our charge ; since the war with Midian was over, they had mustered the several companies under their command, such as had thousands, and those that had hundreds:

and there not one man of us is missing ; which is a most amazing and unheard of thing, that in waging war with a whole nation, slaying all their males, sacking and burning so many cities, plundering the inhabitants of their substance, taking and carrying off such a vast number of captives, yet not one should fall by the sword of the enemy, or by any disease or accident whatever, but all to a man should return to the camp of Israel again; this is not to be paralleled in any history.