8 Now David and his men went up and made raids on the Geshurites, the Girzites, and the Amalekites; for these were the landed settlements from Telam on the way to Shur and on to the land of Egypt. 9 David struck the land, leaving neither man nor woman alive, but took away the sheep, the oxen, the donkeys, the camels, and the clothing, and came back to Achish. 10 When Achish asked, "Against whom have you made a raid today?" David would say, "Against the Negeb of Judah," or "Against the Negeb of the Jerahmeelites," or, "Against the Negeb of the Kenites." 11 David left neither man nor woman alive to be brought back to Gath, thinking, "They might tell about us, and say, "David has done so and so.' " Such was his practice all the time he lived in the country of the Philistines. 12 Achish trusted David, thinking, "He has made himself utterly abhorrent to his people Israel; therefore he shall always be my servant."
Matthew Henry's Commentary on 1 Samuel 27:8-12
Commentary on 1 Samuel 27:8-12
(Read 1 Samuel 27:8-12)
While David was in the land of the Philistines, he attacked some remains of the devoted nations. The people whom he cut off were long before doomed to destruction. It is often wisdom to shun public notice, but we must in no situation be idle. We must always try to do somewhat in the cause of God. This expedition David hid from Achish. But an equivocation which serves the purpose of a lie, is as like to it as a hypocrite is to a profane person, it is only better in appearance, therefore more dangerous. Yet, though believers often manifest imperfections, they can never be prevailed upon to renounce the service of God, and to unite interests with his enemies, or finally to become the servants of sin and Satan. But what a train of evils follow from unbelief! When we forget the Lord's past mercies, and his gracious assurances, we shall be overwhelmed with desponding fears, and probably be led to adopt some dishonourable method to get rid of our troubles. Nothing can so effectually establish us in holy tempers and practices, and preserve us from perplexities, as firm, unshaken dependence upon the promises of God in Christ Jesus.