The angel of the Lord was a special heavenly messenger through whom God acted on earth. Often, he delivered important messages (see Genesis 16:7–14), but sometimes he brought judgment (see 2 Samuel 24:16).
struck down 185,000 men: The Lord began to fulfill his repeated promises: rescue of Jerusalem and judgment of Assyria (see Isaiah 10:16, 33–34; 30:31; 31:8).