Charles Ellicott Commentary Deuteronomy 32:42

"I will make mine arrows drunk with blood, And my sword shall devour flesh; With the blood of the slain and the captives, From the head of the leaders of the enemy." — Deuteronomy 32:42 (ASV)

My sword shall devour flesh. Compare Isaiah 66:16: “For by fire and by His sword will the Lord plead with all flesh, and the slain of the Lord shall be many.”

With blood. Literally, from the blood of the slain and of the captives, from the beginning of vengeance upon the enemy. Judgment must begin at the house of God, as it did in Ezekiel’s vision (Ezekiel 9:6), “and begin at my sanctuary;” but it will not end there.