The Kenites; a people descending from or nearly related unto Jethro, who anciently dwelt in rocks near the Amalekites, Numbers 24:21, and afterwards some of them dwelt in Judah, Judges 1:16, whence it is probable they removed, (which, dwelling in tents, they could easily do,) and retired to their old habitation, because of the wars and troubles wherewith Judah was annoyed. Ye showed kindness; some of your progenitors did so, Exodus 18:12 Numbers 10:31, and for their sakes all of you shall fare the better. You were not guilty of that sin for which Amalek is now to be destroyed.
Related Commentaries of 1 Samuel 15:6
1 Samuel 15:6
6 And Saul said unto the Kenites, Go, depart, get you down from among the Amalekites, lest I destroy you with them: for ye shewed kindness to all the children of Israel, when they came up out of Egypt. So the Kenites departed from among the Amalekites.