A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
1 Kings (1 Samuel) 26:1
sa1 26:1SAUL COMES TO THE HILL OF HACHILAH AGAINST DAVID. (Sa1 26:1-4)
the Ziphites came unto Saul to Gibeah--This people seem to have thought it impossible for David to escape, and therefore recommended themselves to Saul, by giving him secret information (see on Sa1 23:19). The knowledge of their treachery makes it appear strange that David should return to his former haunt in their neighborhood; but, perhaps he did it to be near Abigail's possessions, and under the impression that Saul had become mollified. But the king had relapsed into his old enmity. Though Gibeah, as its name imports, stood on an elevated position, and the desert of Ziph, which was in the hilly region of Judea, may have been higher than Gibeah, it was still necessary to descend in leaving the latter place; thence Saul (Sa1 26:2) "went down to the wilderness of Ziph."
1 Kings (1 Samuel) 26:4
sa1 26:4David . . . sent out spies . . . and David arose, and came to the place where Saul had pitched--Having obtained certain information of the locality, he seems, accompanied by his nephew (Sa1 26:6), to have hid himself, perhaps disguised, in a neighboring wood, or hill, on the skirts of the royal camp towards night, and waited to approach it under covert of the darkness.
1 Kings (1 Samuel) 26:5
sa1 26:5DAVID STAYS ABISHAI FROM KILLING SAUL, BUT TAKES HIS SPEAR AND CRUSE. (1Sa. 26:5-25)
Saul lay in the trench, and the people pitched round about him--Among the nomad people of the East, the encampments are usually made in a circular form. The circumference is lined by the baggage and the men, while the chief's station is in the center, whether he occupy a tent or not. His spear, stuck in the ground, indicates his position. Similar was the disposition of Saul's camp--in this hasty expedition he seems to have carried no tent, but to have slept on the ground. The whole troop was sunk in sleep around him.
1 Kings (1 Samuel) 26:8
sa1 26:8Then said Abishai to David, God hath delivered thine enemy into thine hand--This midnight stratagem shows the activity and heroic enterprise of David's mind, and it was in unison with the style of warfare in ancient times.
let me smite him . . . even to the earth at once--The ferocious vehemence of the speaker is sufficiently apparent from his language, but David's magnanimity soared far above the notions of his followers. Though Saul's cruelty and perfidy and general want of right principle had sunk him to a low pitch of degradation, yet that was no reason for David's imitating him in doing wrong. Besides, he was the sovereign; David was a subject. Though God had rejected him from the kingdom, it was in every way the best and most dutiful course, instead of precipitating his fall by imbruing their hands in his blood and thereby contracting the guilt of a great crime, to wait the awards of that retributive providence which sooner or later would take him off by some sudden and mortal blow. He who, with impetuous haste was going to exterminate Nabal, meekly spared Saul. But Nabal refused to give a tribute to which justice and gratitude, no less than custom, entitled David. Saul was under the judicial infatuation of heaven. Thus David withheld the hand of Abishai; but, at the same time, he directed him to carry off some things which would show where they had been, and what they had done. Thus he obtained the best of victories over him, by heaping coals of fire on his head.
1 Kings (1 Samuel) 26:11
sa1 26:11the spear that is at his bolster, and the cruse of water--The Oriental spear had, and still has, a spike at the lower extremity, intended for the purpose of sticking the spear into the ground when the warrior is at rest. This common custom of Arab sheiks was also the practice of the Hebrew chiefs.
at his bolster--literally, "at his head"; perhaps, Saul as a sovereign had the distinguished luxury of a bolster carried for him. A "cruse of water" is usually, in warm climates, kept near a person's couch, as a drink in the night time is found very refreshing. Saul's cruse would probably be of superior materials, or more richly ornamented than common ones, and therefore by its size or form be easily distinguished.
1 Kings (1 Samuel) 26:13
sa1 26:13Then David . . . stood on the top of an hill afar off . . . and cried to the people--(See on Jdg 9:7). The extraordinary purity and elasticity of the air in Palestine enable words to be distinctly heard that are addressed by a speaker from the top of one hill to people on that of another, from which it is separated by a deep intervening ravine. Hostile parties can thus speak to each other, while completely beyond the reach of each other's attack. It results from the peculiar features of the country in many of the mountain districts.
1 Kings (1 Samuel) 26:15
sa1 26:15David said to Abner, Art not thou a valiant man: . . . wherefore then hast thou not kept thy lord the king?--The circumstance of David having penetrated to the center of the encampment, through the circular rows of the sleeping soldiers, constituted the point of this sarcastic taunt. This new evidence of David's moderation and magnanimous forbearance, together with his earnest and kindly expostulation, softened the obduracy of Saul's heart.
1 Kings (1 Samuel) 26:19
sa1 26:19If the Lord have stirred thee up against me--By the evil spirit He had sent, or by any spiritual offenses by which we have mutually displeased Him.
let him accept an offering--that is, let us conjointly offer a sacrifice for appeasing His wrath against us.
if they be the children of men--The prudence, meekness, and address of David in ascribing the king's enmity to the instigations of some malicious traducers, and not to the jealousy of Saul himself, is worthy of notice.
saying, Go, serve other gods--This was the drift of their conduct. By driving him from the land and ordinances of the true worship, into foreign and heathen countries, they were exposing him to all the seductions of idolatry.
1 Kings (1 Samuel) 26:20
sa1 26:20as 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.
1 Kings (1 Samuel) 26:25
sa1 26:25So David went on his way--Notwithstanding this sudden relenting of Saul, David placed no confidence in his professions or promises, but wisely kept at a distance and awaited the course of Providence.