If the reasons Achish had to trust David were stronger than the reasons which the princes offered why they should distrust him (as I do not see that, in policy, they were, for the princes were certainly in the right), yet Achish was but one of five, though the chief, and the only one that had the title of king; accordingly, in a council of war held on this occasion, he was over-voted, and obliged to dismiss David, though he was extremely fond of him. Kings cannot always do as they would, nor have such as they would about them.
I. The discharge Achish gives him is very honourable, and not a final discharge, but only from the present service. 1. He signifies the great pleasure and satisfaction he had taken in him and in his conversation: Thou art good in my sight as an angel of God, Sa1 29:9. Wise and good men will gain respect, wherever they go, from all that know how to make a right estimate of persons and things, though of different professions in religion. What Achish says of David, God, by the prophet, says of the house of David (Zac 12:8), that it shall be as the angel of the Lord. But the former is a court-compliment; the latter is a divine promise. 2. He gives him a testimonial of his good behaviour, Sa1 29:6. It is very full and in obliging terms: "Thou hast been upright, and thy whole conduct has been good in my sight, and I have not found evil in thee." Saul would not have given him such a testimonial, though he had done far more service to him than Achish. God's people should behave themselves always so inoffensively as if possible to get the good word of all they have dealings with; and it is a debt we owe to those who have acquitted themselves well to give them the praise of it. 3. He lays all the blame of his dismission upon the princes, who would by no means suffer him to continue in the camp. "The king loves thee entirely, and would venture his life in thy hand; but the lords favour thee not, and we must not disoblige them, nor can we oppose them; therefore return and go in peace." He had better part with his favourite than occasion a disgust among his generals and a mutiny in his army. Achish intimates a reason why they were uneasy. It was not so much for David's own sake as for the sake of his soldiers that attended him, whom he calls his master's servants (namely, Saul's), Sa1 29:10. They could trust him, but not them. (4.) He orders him to be gone early, as soon as it was light (Sa1 29:10), to prevent their further resentments, and the jealousies they would have been apt to conceive if he had lingered.
II. His reception of this discourse is very complimental; but, I fear, not without some degree of dissimulation. "What?" says David, "must I leave my lord the king, whom I am bound by office to protect, just now when he is going to expose himself in the field? Why may not I go and fight against the enemies of my lord the king?" Sa1 29:8. He seemed anxious to serve him when he was at this juncture really anxious to leave him, but he was not willing that Achish should know that he was. No one knows how strong the temptation is to compliment and dissemble which those are in that attend great men, and how hard it is to avoid it.
III. God's providence ordered it wisely and graciously for him. For, besides that the snare was broken and he was delivered out of the dilemma to which he was first reduced, it proved a happy hastening of him to the relief of his own city, which sorely wanted him, though he did not know it. Thus the disgrace which the lords of the Philistines put upon him prove, in more ways than one, an advantage to him. The steps of a good man ore ordered by the Lord, and he delighteth in his way. What he does with us we know not now, but we shall know hereafter, and shall see it was all for good.

As an angel of God - There is some reason to think that Achish had actually embraced or was favourably disposed towards the Jewish religion. He speaks here of the angels of God, as a Jew might be expected to speak; and in Sa1 29:6 he appeals to, and swears by Jehovah; which, perhaps, no Philistine ever did. It is possible that he might have learned many important truths from David, during the time he sojourned with him.

And Achish answered and said unto David,.... In reply to the questions:

I know that thou art good in my sight as an angel of God: for his great wisdom, and graceful behaviour, and inoffensive carriage:

notwithstanding the princes of the Philistines have said, he shall not go up with us to the battle; though Achish had so good an opinion of him, and had declared it in council, yet an order had passed there that he should not go to battle with them; there were but five of them, and Achish was one of the five, so that there were four to one for the dismissing him; and Achish, though a king, was obliged to submit.

notwithstanding the princes of the Philistines have said--The Philistine government had constitutional checks--or at least the king was not an absolute sovereign; but his authority was limited--his proceedings liable to be controlled by "the powerful barons of that rude and early period--much as the kings of Europe in the Middle Ages were by the proud and lawless aristocracy which surrounded them" [CHALMERS].

Next: 1 Samuel Chapter 30