8 and brought the head of Ish-bo'sheth to David at Hebron. And they said to the king, "Here is the head of Ish-bo'sheth, the son of Saul, your enemy, who sought your life; the Lord has avenged my lord the king this day on Saul and on his offspring."
9 But David answered Rechab and Ba'anah his brother, the sons of Rimmon the Be-er'othite, "As the Lord lives, who has redeemed my life out of every adversity, 10 when one told me, 'Behold, Saul is dead,' and thought he was bringing good news, I seized him and slew him at Ziklag, which was the reward I gave him for his news. 11 How much more, when wicked men have slain a righteous man in his own house upon his bed, shall I not now require his blood at your hand, and destroy you from the earth?" 12 And David commanded his young men, and they killed them, and cut off their hands and feet, and hanged them beside the pool at Hebron. But they took the head of Ish-bo'sheth, and buried it in the tomb of Abner at Hebron.
Matthew Henry's Commentary on 2 Samuel 4:8-12
Commentary on 2 Samuel 4:8-12
(Read 2 Samuel 4:8-12)
A person may be glad to obtain his just wishes, and yet really regret the means by which he receives them. He may be sorry for the death of a person by which he is a gainer. These men shed innocent blood, from the basest motives. David justly executed vengeance upon them. He would not be beholden to any to help him by unlawful practices. God had helped him over many a difficulty, and through many a danger, therefore he depended upon him to crown and complete his own work. He speaks of his redemption from all adversity, as a thing done; though he had many storms yet before him, he knew that He who had delivered, would deliver.