THEOSISTheodoret of Cyrus
Why did David spare Joab's life following this wrongful act of murder? He clarified his decision through his own words, stating, "These men, the sons of Zeruiah, are the most ruthless" (2 Sam. 3:39); thus, he entrusted their fate to God, proclaiming, “that the Lord may repay the evildoer according to his wickedness” (ibid.). In moments where David had the opportunity to express just indignation, he chose to show no mercy. He executed those responsible for Mephibosheth's demise and had their hands and feet severed, even though they believed that by overthrowing their ruler they were surrendering the entire kingdom of Israel to David. He dealt with the murderer by sentencing him to death while permitting the burial of the adversary's head with dignity (2 Sam. 4:12).