If ye had saved them alive, &c. For, as they were not Canaanites, he was not obliged by any command of God to put them to death: but as they had killed his brethren, and that, it seems, in cold blood, he was, by God's law, the avenger of their death, being their near kinsman.
Related Commentaries of Judges 8:19
Judges 8:19
19 And he said, They were my brethren, even the sons of my mother: as the LORD liveth, if ye had saved them alive, I would not slay you.