(10) And David said, Against the south of Judah.--The answer of David to his sovereign lord, the King of Gath--for he was now, to all intents and purposes, a vassal prince of Achish--was simply a falsehood. He had been engaged in distant forays against the old Bedaween enemies of Israel, far away in the desert which stretched to the frontier of Egypt; and from these nomads--rich in cattle and in other property, which they had obtained by years of successful plunder--he seems to have gained much booty, a share of which he brought to his "suzerain," Achish. But David represents that the cattle and apparel had been captured from his own countrymen, whose territory he was harrying. "The Jerahmeelites were descendants of Jerahmeel, the firstborn of Hezron (1Chronicles 2:9; 1Chronicles 2:25-26), and therefore one of the three large families of Judah who sprang from Hezron."--Keil, They dwelt, it is believed, on the southern frontier of the tribe of Judah. The Kenites were a race living in friendship with and under the protection of Judah.

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.And Achish said, whither have ye made a road today?.... Or whither had they rushed in, or poured in and spread themselves? or where had they made their excursion to fetch in the prey and booty they now brought?

and David said, against the south of Judah; he meant against some people that lay to the south of the land of Judah, without it; but expressed himself so, that Achish might think he meant the southern parts of Judah within the country; which, though not a downright lie, was an equivocation, and made with a design to deceive; and was by no means agreeably to the character of David, nor to be defended nor imitated:

and against the south of the Jerahmeelites; these were the descendants of Jerahmeel, the son of Hezron, the grandson of Judah, and so inhabited in the tribe of Judah, and very probably in the southern part of it, 1 Chronicles 2:9,

and against the south of the Kenites; the posterity of Jethro; these, at least some of them, at the first seating of the children of Israel in the land of Canaan, went with the children of Judah into the wilderness of Judah, which lieth in the south of Arad, Judges 1:16.