Commentary on the Bible, by Adam Clarke, [1831], at sacred-texts.com
The Philistines gather their armies together against Israel, and encamp at Aphek; while the Israelites encamp at Jezreel, Sa1 29:1. The lords of the Philistines refuse to let David go to battle with them, lest he should betray them, Sa1 29:2-5. Achish expresses his confidence in David; but begs him to return, Sa1 29:6-10. David and his men return, Sa1 29:11.
To Aphek - This was a place in the valley of Jezreel, between Mounts Tabor and Gilboa.
Pitched by a fountain - To be near a fountain, or copious spring of water, was a point of great importance to an army in countries such as these, where water was so very scarce. It is supposed, as William of Tyre says, that it was at this same fountain that Saladin pitched his camp, while Baldwin, king of Jerusalem, pitched his by another fountain between Nazareth and Sephoris; each being anxious to secure that without which it was impossible for their armies to subsist.
By hundreds, and by thousands - They were probably divided, as the Jewish armies, by fifties, hundreds, and thousands; each having its proper officer or captain.
These days, or these years - I suppose these words to mark no definite time, and may be understood thus: "Is not this David, who has been with me for a considerable time?"
The princes of the Philistines were wroth - It is strange that they had not yet heard of David's destruction of a village of the Geshurites, Gezrites, and Amalekites, Sa1 27:8, Sa1 27:9. Had they heard of this, they would have seen much more cause for suspicion.
Thou hast been upright - So he thought, for as yet he had not heard of the above transaction; David having given him to understand that he had been fighting against Israel.
David said - what have I done? - Dr. Chandler and others may say what they will to make David act a consistent part in this business; but it is most evident, whatever his intentions might be as to the part he was to take in the approaching battle, he did intend to persuade Achish that he would fight against Israel; and affects to feel his reputation injured by not being permitted on this occasion to show his fidelity to the king of Gath.
It was in the order of God's gracious providence that the Philistine lords refused to let David go with them to this battle. Had he gone, he had his choice of two sins - First, If he had fought for the Philistines, he would have fought against God and his country. Secondly If he had in the battle gone over to the Israelites, he would have deceived and become a traitor to the hospitable Achish. God, therefore, so ordered it in his mercy that he was not permitted to go to a battle in which he was sure to be disgraced, whatever side he took, or with what success soever he might be crowned.
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.
With thy master's servants - Who were these? has been very properly asked; and to this question there can be but two answers: -
1. The six hundred Israelites which were with him; and who might still be considered the subjects of Saul, though now residing in a foreign land.
2. The servants of achish; i.e., David's men thus considered; because on his coming to Gath, he had in effect given up himself and his men to Achish. But Saul may be the master to whom Achish refers, and the words convey a delicate information to David that he is no vassal, but still at liberty.