30:7-15 If in all our ways, even when, as in this case, there can be no doubt they are just, we acknowledge God, we may expect that he will direct our steps, as he did those of David. David, in tenderness to his men, would by no means urge them beyond their strength. The Son of David thus considers the frames of his followers, who are not all alike strong and vigorous in their spiritual pursuits and conflicts; but, where we are weak, there he is kind; nay more, there he is strong, 2Co 12:9,10. A poor Egyptian lad, scarcely alive, is made the means of a great deal of good to David. Justly did Providence make this poor servant, who was basely used by his master, an instrument in the destruction of the Amalekites; for God hears the cry of the oppressed. Those are unworthy the name of true Israelites, who shut up their compassion from persons in distress. We should neither do an injury nor deny a kindness to any man; some time or other it may be in the power of the lowest to return a kindness or an injury.
11-15. they found an Egyptian in the field, and brought him to David—Old and homeborn slaves are usually treated with great kindness. But a purchased or captured slave must look to himself; for, if feeble or sick, his master will leave him to perish rather than encumber himself with any additional burden. This Egyptian seems to have recently fallen into the hands of an Amalekite, and his master having belonged to the marauding party that had made the attack on Ziklag, he could give useful information as to the course taken by them on their return.