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) 20:1
sa1 20:1DAVID CONSULTS WITH JONATHAN FOR HIS SAFETY. (Sa1 20:1-10)
David fled from Naioth in Ramah, and came and said before Jonathan--He could not remain in Naioth, for he had strong reason to fear that when the religious fit, if we may so call it, was over, Saul would relapse into his usual fell and sanguinary temper. It may be thought that David acted imprudently in directing his flight to Gibeah. But he was evidently prompted to go thither by the most generous feelings--to inform his friend of what had recently occurred, and to obtain that friend's sanction to the course he was compelled to adopt. Jonathan could not be persuaded there was any real danger after the oath his father had taken; at all events, he felt assured his father would do nothing without telling him. Filial attachment naturally blinded the prince to defects in the parental character and made him reluctant to believe his father capable of such atrocity. David repeated his unshaken convictions of Saul's murderous purpose, but in terms delicately chosen (Sa1 20:3), not to wound the filial feelings of his friend; while Jonathan, clinging, it would seem, to a hope that the extraordinary scene enacted at Naioth might have wrought a sanctified improvement on Saul's temper and feelings, undertook to inform David of the result of his observations at home.
1 Kings (1 Samuel) 20:5
sa1 20:5David said unto Jonathan, Behold, to-morrow the new moon, and I should not fail to sit with the king at meat--The beginning of a new month or moon was always celebrated by special sacrifices, followed by feasting, at which the head of a family expected all its members to be present. David, both as the king's son-in-law and a distinguished courtier, dined on such occasions at the royal table, and from its being generally known that David had returned to Gibeah, his presence in the palace would be naturally expected. This occasion was chosen by the two friends for testing the king's state of feeling. As a suitable pretext for David's absence, it was arranged that he should visit his family at Beth-lehem, and thus create an opportunity of ascertaining how his non-appearance would be viewed. The time and place were fixed for Jonathan reporting to David; but as circumstances might render another interview unsafe, it was deemed expedient to communicate by a concerted signal.
1 Kings (1 Samuel) 20:11
sa1 20:11THEIR COVENANT RENEWED BY OATH. (Sa1 20:11-23)
Jonathan said to David, Come, let us go into the field--The private dialogue, which is here detailed at full length, presents a most beautiful exhibition of these two amiable and noble-minded friends. Jonathan was led, in the circumstances, to be the chief speaker. The strength of his attachment, his pure disinterestedness, his warm piety, his invocation to God (consisting of a prayer and a solemn oath combined), the calm and full expression he gave of his conviction that his own family were, by the divine will, to be disinherited, and David elevated to the possession of the throne, the covenant entered into with David on behalf of his descendants, and the imprecation (Sa1 20:16) denounced on any of them who should violate his part of the conditions, the reiteration of this covenant on both sides (Sa1 20:17) to make it indissoluble--all this indicates such a power of mutual affection, such magnetic attractiveness in the character of David, such susceptibility and elevation of feeling in the heart of Jonathan, that this interview for dramatic interest and moral beauty stands unrivalled in the records of human friendship.
1 Kings (1 Samuel) 20:19
sa1 20:19when thou hast stayed three days--either with your family at Beth-lehem, or wherever you find it convenient.
come to the place where thou didst hide thyself when the business was in hand--Hebrew, "in the day," or "time of the business," when the same matter was under inquiry formerly (Sa1 19:22).
remain by the stone Ezel--Hebrew, "the stone of the way"; a sort of milestone which directed travellers. He was to conceal himself in some cave or hiding-place near that spot.
1 Kings (1 Samuel) 20:23
sa1 20:23as touching the matter which thou and I have spoken of--The plan being concerted, the friends separated for a time, and the amiable character of Jonathan again peers out in his parting allusion to their covenant of friendship.
1 Kings (1 Samuel) 20:25
sa1 20:25SAUL, MISSING DAVID, SEEKS TO KILL JONAHAN. (1Sa. 20:24-40)
the king sat upon his seat, as at other times . . . by the wall--The left-hand corner at the upper end of a room was and still is in the East, the most honorable place. The person seated there has his left arm confined by the wall, but his right hand is at full liberty. From Abner's position next the king, and David's seat being left empty, it would seem that a state etiquette was observed at the royal table, each of the courtiers and ministers having places assigned them according to their respective gradations of rank.
Jonathan arose--either as a mark of respect on the entrance of the king, or in conformity with the usual Oriental custom for a son to stand in presence of his father.
1 Kings (1 Samuel) 20:26
sa1 20:26he is not clean--No notice was taken of David's absence, as he might be laboring under some ceremonial defilement.
1 Kings (1 Samuel) 20:27
sa1 20:27on the morrow, which was the second day of the month--The time of the moon's appearance being uncertain--whether at midday, in the evening, or at midnight, the festival was extended over two days. Custom, not the law, had introduced this.
Saul said unto Jonathan his son, Wherefore cometh not the son of Jesse--The question was asked, as it were, casually, and with as great an air of indifference as he could assume. And Jonathan having replied that David had asked and obtained his permission to attend a family anniversary at Beth-lehem [Act 20:28-29], the pent-up passions of the king burst out in a most violent storm of rage and invective against his son.
1 Kings (1 Samuel) 20:30
sa1 20:30Thou son of the perverse rebellious woman--This is a striking Oriental form of abuse. Saul was not angry with his wife; it was the son alone, upon whom he meant, by this style of address, to discharge his resentment. The principle on which it is founded seems to be, that to a genuine filial instinct it is a more inexpiable offense to hear the name or character of a parent traduced, than any personal reproach. This was, undoubtedly, one cause of "the fierce anger" in which the high-minded prince left the table without tasting a morsel.
1 Kings (1 Samuel) 20:33
sa1 20:33Saul cast a javelin at him--This is a sad proof of the maniacal frenzy into which the unhappy monarch was transported.
1 Kings (1 Samuel) 20:35
sa1 20:35Jonathan went out into the field at the time appointed--or, "at the place appointed."
1 Kings (1 Samuel) 20:36
sa1 20:36he said unto his lad, Run, find out now the arrows which I shoot--The direction given aloud to the attendant was the signal preconcerted with David. It implied danger.
1 Kings (1 Samuel) 20:40
sa1 20:40Jonathan gave his artillery unto his lad--that is, his missive weapons. The French word artillerie, signifies "archery." The term is still used in England, in the designation of the "artillery company of London," the association of archers, though they have long disused bows and arrows. Jonathan's boy being despatched out of the way, the friends enjoyed the satisfaction of a final meeting.
1 Kings (1 Samuel) 20:41
sa1 20:41JONATHAN AND DAVID LOVINGLY PART. (Sa1 20:41-42)
David . . . fell on his face to the ground, and bowed three times--a token of homage to the prince's rank; but on a close approach, every other consideration was sunk in the full flow of the purest brotherly affection.
1 Kings (1 Samuel) 20:42
sa1 20:42Jonathan said to David, Go in peace--The interview being a stolen one, and every moment precious, it was kindness in Jonathan to hasten his friend's departure.