I Samuel 24:14

And even if he should wish to attack the king, he did not possess the power. This thought introduces Sa1 24:14 : "After whom is the king of Israel gone out? After whom dost thou pursue? A dead dog, a single flea." By these similes David meant to describe himself as a perfectly harmless and insignificant man, of whom Saul had no occasion to be afraid, and whom the king of Israel ought to think it beneath his dignity to pursue. A dead dog cannot bite or hurt, and is an object about which a king ought not to trouble himself (cf. Sa2 9:8 and Sa2 16:9, where the idea of something contemptible is included). The point of comparison with a flea is the insignificance of such an animal (cf. Sa1 26:20).

We have hitherto had Saul seeking an opportunity to destroy David, and, to his shame, he could never find it. In this chapter David had a fair opportunity to destroy Saul, and, to his honour, he did not make use of it; and his sparing Saul's life was as great an instance of God's grace in him as the preserving of his own life was of God's providence over him. Observe, I. How maliciously Saul sought David's life (Sa1 24:1, Sa1 24:2). II. How generously David saved Saul's life (when he had him at an advantage) and only cut off the skirt of his robe (Sa1 24:3-8). III. How pathetically he reasoned with Saul, upon this to bring him to a better temper towards him (Sa1 24:9-15). IV. The good impression this made upon Saul for the present (Sa1 24:16-22).