שמואל א, פרק כ׳, פסוק ט״ז

The bond of friendship between David and Jonathan reaches a new level of strength as their promises to one another become fully mutual. While David previously committed to safeguarding Jonathan's future descendants, Jonathan now takes on an immediate, heavy responsibility to protect David's family. As David becomes a hunted man forced into hiding, Jonathan pledges to use his royal position and influence to shield David's household. This protective promise extends to David's wife Michal, his sons, his father Jesse's family, and even his loyal friends and servants [מלבי״ם, רדַ״ק, אברבנאל]. Jonathan commits to doing everything in his power to ensure that Saul does not harm them [מלבי״ם, מצודת דוד, רדַ״ק, אברבנאל].

Accompanying this deep pledge of loyalty is a solemn declaration about divine justice, which carries several layers of meaning. On a straightforward level, it serves as a stern warning that God will ultimately punish anyone who opposes David. Jonathan even includes himself in this warning, acknowledging that if he were to break his promise and fail to show kindness, God would hold him accountable as an enemy [מצודת דוד, ביאור שטיינזלץ]. Alternatively, this declaration can be understood as a heartfelt prayer. During the making of the covenant, Jonathan asks God for the strength and divine help needed to fulfill his difficult promise of saving David's family from those who wish them harm [מלבי״ם].

A completely different approach suggests that speaking about those who oppose David is actually a polite, indirect way of referring to David himself. In this view, Jonathan is adding a strict condition to their agreement, warning David that if he ever violates their covenant, God will hold him personally responsible [רש״י, רדַ״ק, חומת אנך]. Commentators note that this specific warning eventually came true. Years later, David compromised the spirit of their friendship when he ordered Jonathan's son, Mephibosheth, to divide his land with his servant Ziba. Because of this failure to fully honor the covenant, a heavenly voice declared a direct consequence: just as the land was divided, David's own kingdom would later be split between Rehoboam and Jeroboam [רש״י, חומת אנך].