Notes on the Bible, by Albert Barnes, [1834], at sacred-texts.com
The rocks of the wild goats - To signify the craggy precipitous character of the country.
Remained in the sides - Rather, "were in the sides of the cave dwelling or abiding there." Some of these caverns are very deep and spacious. Any one near the mouth of the cave would be visible, but those in the recesses would be quite in the dark and invisible, especially if the incident occurred at night. Psa 67:1-7, according to the title, was composed on this occasion.
The day of which the Lord said ... - This was the version by David's men of such divine predictions as Sa1 15:28; Sa1 16:1, Sa1 16:12. Jonathan's words Sa1 20:15; Sa1 23:17 show clearly that these predictions were known.
David's heart smote him - He thought the action inconsistent with the respect which he owed to the king.
David was quite aware that there were flatterers at Saul's court who were continually inflaming the King's mind by their false accusations against him. This explains the language of many of the Psalms, e. g. Ps. 10; Psa 11:1-7; Psa 12:1-8; 35; and many more.
My father - The respectful address of a junior and an inferior (see Kg2 5:13, and compare Sa1 24:16; Sa1 25:8).
After whom ... - i. e., was it consistent with the dignity of the king of Israel to lead armies in pursuit of a weak and helpless individual like David?
Swear now ... - The same request which Jonathan made Sa1 20:15. The deep, genealogical feeling of the Israelites breaks out here as so often elsewhere.
Saul does not appear to have invited David to return to Gibeah, or to have given him any security of doing so with safety. David, with his intuitive sagacity, perceived that the softening of Saul's feelings was only momentary, and that the situation remained unchanged.