John Gill's Bible Commentary Ver. 5. [Is] not this David, of whom they sang one to another in dances , etc.] Long ago: saying, Saul slew his thousands, and David his ten thousands ; so that he is an old sworn enemy of ours; and the more valiant and victorious he has been, the less is he to be trusted, (see 1 Samuel 18:7 21:11).
Matthew Henry Commentary
Verses 1-5 - David waited with a secret hope that the Lord would help him out of his difficulty. But he seems to have been influenced too much by the fea of man, in consenting to attend Achish. It is hard to come near to the brink of sin, and not to fall in. God inclined the princes of the Philistines to oppose David's being employed in the battle. Thus their dislike befriended him, when no friend could do him such a kindness.
Original Hebrew הלוא3808 זה2088 דוד1732 אשׁר834 יענו6030 לו במחלות4246 לאמר559 הכה5221 שׁאול7586 באלפיו505 ודוד1732 ברבבתו׃7233