The previous paragraph had Jonathan joining into a covenant with David, but here he actually agrees to the plan and gives David permission to leave. The plan as outlined by David had one flaw (ויאמר דוד אל יהונתן מי יגיד לי): how could Jonathan get the information to David without being found by Saul’s spies? Jonathan now has the answer: a code in an apparently innocuous message. Note the subtlety in the language. If everything is good, Jonathan will talk to the נער. If David needs to hide, Jonathan will talk to the עלם, which also means “youth” but has a midrashic implication of “hidden”; “the youth with a hidden message”. We saw this when Saul asked about David’s ancestry:
נה וכראות שאול את דוד יצא לקראת הפלשתי אמר אל אבנר שר הצבא בן מי זה הנער אבנר; ויאמר אבנר חי נפשך המלך אם ידעתי׃ נו ויאמר המלך: שאל אתה בן מי זה העלם׃
שמואל א פרק יז
Jonathan will come out to David by the יום המעשה, which the Targum translates as יומא דחולא, the profane day. ראש חדש is not a day for work; not a real יום טוב but women have the מנהג not to do מלכאה, and the מרדכי adds that מלאכה כבידה should be avoided. The משבצות זהב explains that this is why David could hide in the field for three days; no one would be working the fields over ראש חדש.
Jonathan then re-emphasizes the covenant. If David has to flee, Jonathan will protect him. When David becomes king, Jonathan and his family will remain safe.
Note the emphasis on Saul’s seat: וישב המלך על מושבו כפעם בפעם אל מושב הקיר. I think this is showing us Saul’s paranoia, that he made sure to keep his back to the wall so no one could sneak up on him.
What does it mean that ויקם יהונתן וישב אבנר? Rashi explains that as a matter or respect, Jonathan would not sit next to Saul unless David was present. It is still hard to put the order of events together. The משבצות זהב brings an explanation that adduces the hierarchy of the original מסורה:
I would interpret this as a matter of protocol. Saul’s entourage would enter one by one, present themselves, then sit by him in order. Jonathan came in but when he stood in order to take his seat, instead of David sitting by Saul, Avner came in. Thus the מקום דוד that was noticed was not David’s seat that was empty, but his place in line.
The רלב״ג explains the duplication of בלתי טהור הוא כי לא טהור as מקרה הוא—an incident happened; he is a בעל קרי, so בלתי טהור הוא, he is impure and it would be rude to come to a state dinner (likely with a זבח שלמים) in a state of טומאה. This is likely because David is לא טהור in general; he is a man of war and of passion, so this sort of thing has happened before.
Saul’s outburst is astonishing; what kind of thing is that for a מלך ישראל to say? The מלבי״ם interprets נעות המרדות as a “twisted rebellion”. It would at least be understandable if Jonathan were to rebel in order to become king himself; that happens all the time (and will happen a few times to David). But this rebelling to make a stranger king, makes no sense at all.
But what is לבשת ערות אמך? רד״ק explains that if you support a stranger, people will say you aren’t really my son, that your mother was unfaithful. מלבי״ם explains that it is a direct insult to your mother; she should be the Queen Mother and you will take that away from her (even if you do not care about your own honor). רש״י connects this with the aftermath of the פלגש בגבעה, when בני בנימן were almost wiped out and took the women from יבש גלעד:
And thus Jonathan was following in his mother’s footsteps in being more outgoing than is proper. But that can’t be taken literally, as רש״י himself holds that פלגש בגבעה happened right after Joshua’s death
Jonathan’s response has implications l’halacha:
The משבצות זהב explains both the repetition of Jonathan’s statements and his apparent lying about the location of the arrows. Jonathan shot three arrows, one at a time. After the first shot (הוא ירה החצי), the lad ran to its location and Jonathan shot another arrow past the first and told him that it was past him (הלוא החצי ממך והלאה), then shot the third even farther and told the lad to run fast (מהרה חושה אל תעמד). Thus the קרי/כתיב of החצי (החצים); there were three arrows with one message.
Then, despite all the careful planning, David can’t control himself and comes out of hiding to say goodbye to Jonathan one last time (they will in fact see each other briefly one more time). It’s a powerful and emotional moment, and we don’t have any evidence that they were observed, but we will see that the plan starts to fall apart very quickly.