Here is, I. Saul's penitent confession of his fault and folly in persecuting David and his promise to do so no more. This second instance of David's respect to him wrought more upon him than the former, and extorted from him better acknowledgements, Sa1 26:21. 1. He owns himself melted and quite overcome by David's kindness to him: "My soul was precious in thy eyes this day, which, I thought, had been odious!" 2. He acknowledges he has done very wrong to persecute him, that he has therein acted against God's law (I have sinned), and against his own interest (I have played the fool), in pursuing him as an enemy who would have been one of his best friends, if he could but have thought so. "Herein (says he) I have erred exceedingly, and wronged both thee and myself." Note, Those that sin play the fool and err exceedingly, those especially that hate and persecute God's people, Job 19:28. 3. He invites him to court again: Return, my son David. Those that have understanding will see it to be their interest to have those about them that behave themselves wisely, as David did, and have God with them. 4. He promises him that he will not persecute him as he has done, but protect him: I will no more do thee harm. We have reason to think, according to the mind he was now in, that he meant as he said, and yet neither his confession nor his promise of amendment came from a principle of true repentance.
II. David's improvement of Saul's convictions and confessions and the evidence he had to produce of his own sincerity. He desired that one of the footmen might fetch the spear (Sa1 26:22), and then (Sa1 26:23), 1. He appeals to God as judge of the controversy: The Lord render to every man his righteousness. David, by faith, is sure that he will do it because he infallibly knows the true characters of all persons and actions and is inflexibly just to render to every man according to his work, and, by prayer, he desires he would do it. Herein he does, in effect, pray against Saul, who had dealt unrighteously and unfaithfully with him (Give them according to their deeds, Psa 28:4); but he principally intends it as a prayer for himself, that God would protect him in his righteousness and faithfulness, and also reward him, since Saul so ill requited him. 2. He reminds Saul again of the proof he had now given of his respect to him from a principle of loyalty: I would not stretch forth my hand against the Lord's anointed, intimating to Saul that the anointing oil was his protection, for which he was indebted to the Lord and ought to express his gratitude to him (had he been a common person David would not have been so tender of him), perhaps with this further implication, that Saul knew, or had reason to think, David was the Lord's anointed too, and therefore, by the same rule, Saul ought to be as tender of David's life as David had been of his. 3. Not relying much upon Saul's promises, he puts himself under God's protection and begs his favour (Sa1 26:24): "Let my life be much set by in the eyes of the Lord, how light soever thou makest of it." Thus, for his kindness to Saul, he takes God to be his paymaster, which those may with a holy confidence do that do well and suffer for it.
III. Saul's prediction of David's advancement. He commends him (Sa1 26:25): Blessed be thou, my son David. So strong was the conviction Saul was now under of David's honesty that he was not ashamed to condemn himself and applaud David, even in the hearing of his own soldiers, who could not but blush to think that they had come out so furiously against a man whom their master, when he meets him, caresses thus. He foretels his victories, and his elevation at last: Thou shalt do great things. Note, Those who make conscience of doing that which is truly good may come, by the divine assistance, to do that which is truly great. He adds, "Thou shalt also still prevail, more and more," he means against himself, but is loth to speak that out. The princely qualities which appeared in David - his generosity in sparing Saul, his military authority in reprimanding Abner for sleeping, his care of the public good, and the signal tokens of God's presence with him - convinced Saul that he would certainly be advanced to the throne at last, according to the prophecies concerning him.
Lastly, A palliative cure being thus made of the wound, they parted friends. Saul returned to Gibeah re infect - without accomplishing his design, and ashamed of the expedition he had made; but David could not take his word so far as to return with him. Those that have once been false are not easily trusted another time. Therefore David went on his way. And, after this parting, it does not appear that ever Saul and David saw one another again.

I have sinned - Perhaps the word חטאתי chatathi, "I have sinned," should be read, I have erred, or, have been mistaken. I have taken thee to be a very different man from what I find thee to be. Taken literally it was strictly true. He often purposed the spilling of David's blood; and thus, again and again, sinned against his life.

And David answered and said, behold the king's spear!.... And which perhaps was his sceptre, and which David therefore would not keep, lest it should be thought or said that he had deprived him of an ensign of his royalty, and be interpreted as a token of his design to seize his crown and throne:

and let one of the young men come over and fetch it; for notwithstanding the acknowledgment Saul had made of his sin and folly, David did not choose to carry the spear to him; not caring to trust him, and put himself into his hands, lest the evil spirit should return and come upon him suddenly, and alter his disposition and carriage; nor would he send any of his men with it, whose lives were dear to him, lest they should be seized as traitors, but desires one of Saul's men might be sent for it.

as when one doth hunt a partridge--People in the East, in hunting the partridge and other game birds, pursue them, till observing them becoming languid and fatigued after they have been put up two or three times, they rush upon the birds stealthily and knock them down with bludgeons [SHAW, Travels]. It was exactly in this manner that Saul was pursuing David. He drove him from time to time from his hiding-place, hoping to render him weary of his life, or obtain an opportunity of accomplishing his destruction.