(Note: Clericus is correct in the explanation which he has given: “Although, therefore, this act of Ahab had all the appearance of clemency, it was not an act of true clemency, which ought not to be shown towards violent aggressors, who if released will do much more injury than before, as Benhadad really did. God had given the victory to Ahab, and delivered the guilty king into his hands, that he might inflict punishment upon him, not that he might treat him kindly. And Ahab, who had allowed so many prophets to be slain by his wife Jezebel, had no great clemency at other times.â€)
Even if Ahab had no express command from God to put Benhadad to death, as Saul had in 1Sa 15:3, it was his duty to punish this bitter foe of Israel with death, if only to secure quiet for his own subjects; as it was certainly to be foreseen that Benhadad would not keep the treaty which had been wrung from him by force, as was indeed very speedily proved (see 1Ki 22:1).