Abigail approaches David with profound rhetorical wisdom, seeking to dissuade him from destroying Nabal's household. She masterfully shifts the focus of their encounter from her own personal intervention to the workings of Divine providence. She makes it clear that their sudden meeting is no coincidence. God Himself orchestrated the events, sending her to prevent David from sinning, as God actively protects His pious ones from stumbling [מצודת דוד, אלשיך, אברבנאל, שטיינזלץ]. This divine intervention effectively saves David from multiple severe sins and terrible bloodshed [חומת אנך].
Abigail warns David against taking the law into his own hands and seeking revenge through brute force [רש״י, רלב״ג, שטיינזלץ]. She systematically removes any legal justification he might have for killing Nabal. David cannot claim that Nabal is a rebel against the crown, because David is not yet universally recognized as king, and Saul still sits on the throne [רד״ק, מלבי״ם]. She explains that if God stepped in to prevent this revenge, it is a clear sign that the act is displeasing to Him [אברבנאל]. Furthermore, acting as his own judge and executioner could ultimately bring divine punishment upon David himself [רש״י].
Advancing her argument, Abigail declares that David's enemies should end up just like Nabal. This statement serves as a dual-layered blessing and curse. On one level, she reminds David of his dignity. As a mighty warrior and the future king, it is entirely beneath him to wage war against a foolish, lowly person like Nabal. His true adversaries are Saul and his officers. Therefore, she blesses David that anyone seeking to harm him should remain as powerless and incompetent as Nabal [רד״ק, אברבנאל, מלבי״ם].
On another level, because David held back from personal vengeance, God will step in to fight his battles. Infused with divine inspiration, Abigail prophesies that Nabal's life will soon end at the hands of heaven. She prays that all of David's enemies will meet their ultimate downfall through direct Divine intervention, exactly as Nabal soon will [רש״י, מצודת דוד, אלשיך].