8 And David and his men went up and made attacks on the Geshurites and the Girzites and the Amalekites; for these were the people who were living in the land from Telam on the way to Shur, as far as Egypt. 9 And David again and again made attacks on the land till not a man or a woman was still living; and he took away the sheep and the oxen and the asses and the camels and the clothing; and he came back to Achish. 10 And every time Achish said, Where have you been fighting today? David said, Against the South of Judah and the South of the Jerahmeelites and the South of the Kenites. 11 Not one living man or woman did David ever take back with him to Gath, fearing that they might give an account of what had taken place, and say, This is what David did, and so has he been doing all the time while he has been living in the land of the Philistines. 12 And Achish had belief in what David said, saying, He has made himself hated by all his people Israel, and so he will be my servant for ever.
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.