John Gills Exposition of the Bible Commentary - 2 Samuel 21:19
And there was again a battle in Gob with the Philistines ,.... Another battle with them in the same place: where Elhanan the son of Jaareoregim, a Bethlehemite, slew the brother of Goliath the Gittite ; the word "brother" is rightly supplied from 1 Chronicles 20:5 ; where his name is said to be Lahmi, for not Goliath himself was slain, though some so interpret it, and take Elhanan to be David; so Jarchi, and with which agrees the Targum; but he was slain not at Gob, but in the valley... read more
Matthew Henry's Complete Commentary - 2 Samuel 21:15-22
We have here the story of some conflicts with the Philistines, which happened, as it should seem, in the latter end of David's reign. Though he had so subdued them that they could not bring any great numbers into the field, yet as long as they had any giants among them to be their champions, they would never be quiet, but took all occasions to disturb the peace of Israel, to challenge them, or make incursions upon them. I. David himself was engaged with one of the giants. The Philistines began... read more