2 Samuel 4:8 (BSB)

They brought the head of Ish-bosheth to David at Hebron and said to the king, “Here is the head of Ish-bosheth son of Saul, your enemy who sought your life. Today the LORD has granted vengeance to my lord the king against Saul and his offspring.”

From 2 Samuel 4. Also in the ESV.

Commentary on 2 Samuel 4:8

• Matthew Henry (Presbyterian), Matthew Henry's Complete Commentary on 2 Samuel 4:1-8: Here is, I. The weakness of Saul's house. Still it grew weaker and weaker. 1. As for Ishbosheth, who was in possession of the throne, his hands were feeble, Sa2 4:1. All the strength they ever had was from Abner's support, and now that he was dead he had no spirit left in him.
• John Gill (Reformed Baptist), Exposition of the Old and New Testaments on 2 Samuel 4:8: And David answered Rechab and Baanah his brother, the sons of Rimmon the Beerothite,.... In a manner they did not expect: and said unto them, as the Lord liveth, who hath redeemed my soul out of all adversity; spiritual and temporal, especially the latter is meant, and particularly what he had been brought into by the persecution of Saul, while living, and by those that...
• Jamieson-Fausset-Brown (Reformed), Commentary Critical and Explanatory on the Whole Bible on 2 Samuel 4:8: They brought the head of Ish-bosheth unto David . . . and said, Behold the head of Ish-bosheth--Such bloody trophies of rebels and conspirators have always been acceptable to princes in the East, and the carriers have been liberally rewarded. Ish-bosheth being a usurper, the two assassins thought they were doing a meritorious service to David by removing the only existing obstacle to the union of the two kingdoms.
• Adam Clarke (Methodist), Clarke's Commentary on the Bible on 2 Samuel 4:8: They brought the head - unto David - They thought, as did the poor lying Amalekite, to ingratiate themselves with David by this abominable act.