Charles Ellicott Commentary 1 Samuel 21:11

"And the servants of Achish said unto him, Is not this David the king of the land? did they not sing one to another of him in dances, saying, Saul hath slain his thousands, And David his ten thousands?" — 1 Samuel 21:11 (ASV)

Is not this David? — Some commentators have supposed, but quite needlessly, that it was the sword of Goliath which betrayed the hero's identity; but although David in his humility did not suspect how widespread his fame was, he was evidently as well known in Philistia as in his own land. That popular song, the folk-song of the Israelite maidens, which sang of the prowess of David, the son of Jesse, was no doubt current in frontier towns like Gath, and the fugitive was immediately recognized. We hear of no attempt made on his life or even against his liberty. The feeling among his generous foes was rather admiration mixed with pity, and wonder at seeing the performer of such splendid achievements in poverty and in exile.

David the king. — Here, again, the title king is vaguely used. Neither the people of Gath nor his own countrymen—except, perhaps, for a few select individuals—knew of the sacred anointing by Samuel at Bethlehem. The designation simply means: Is not this the renowned warrior, the greatest man in Israel of whom the people sing? Saul, our sovereign, has been a valiant captain over us, and has slain his thousands; but this one is greater still, he has slain his ten thousands.