The sudden and tragic death of a great military commander prompts a profound lament from a grieving king, exposing the deep gap between an unjustified murder committed by man and the hidden, exact justice of God. This is no ordinary eulogy, but an expression of shock over the fall of a high-ranking leader. A specific lament was composed to honor him, fitting for a great man whose absence would be deeply felt by the entire nation [מלבי״ם]. The king mourned not merely the loss of life, but the entire tragic chain of events that ultimately led to this fatal moment [ראשון לציון].
At the center of the mourning is a deeply unsettling question: how could such a distinguished warrior die the death of a lowly criminal? [ביאור שטיינזלץ]. The primary approach among commentators is that the king was horrified to see a great man die in the manner of a base, wicked person or a common criminal executed by the sword [רש״י, רד״ק, מצודת ציון, ביאור שטיינזלץ]. Another perspective connects this tragedy to the historical figure of Nabal the Carmelite. Just as David previously restrained himself from killing Nabal without a fair trial, he is now deeply shaken that Abner was murdered by Joab without a formal verdict, in complete violation of the law [ראשון לציון].
David's cry stems from the sheer disbelief that such a mighty hero met his end outside the battlefield, unable to defend himself or fight back against his attacker [רד״ק, מצודת דוד]. Furthermore, Abner was not a sinner who deserved such a fate at the hands of another man. Joab's act of killing him, supposedly to avenge the blood of his brother Asahel, was a severe injustice. Abner had only killed Asahel in absolute self-defense while being pursued, meaning he did not deserve the death penalty [ביאור שטיינזלץ, ראשון לציון].
Yet, beneath the grief over this human injustice lies an acknowledgment of heavenly judgment. Even though Joab acted unlawfully and killed him through deception, Abner's death was ultimately decreed by God as a punishment for past failures. Abner was held accountable for failing to effectively protest King Saul's massacre of the priests of the city of Nob. Additionally, he was punished for delaying the rightful establishment of the Davidic dynasty by two and a half years when he crowned Ish-bosheth. Finally, he had previously spoken poorly of David, which fueled Saul's cruelty and prolonged his relentless pursuit [ראשון לציון].