John Gill Bible Commentary

How much more, when wicked men have slain a righteous person,.... As Ishbosheth was in comparison of the wicked men that slew him; though not with respect to David, if he knew of his divine designation to the throne; nor with respect to Mephibosheth his eldest brother's son, whose right to the throne was prior to his, which he must know; though with respect to his conduct towards David, in assuming the throne of Israel, it might not be owing to any bad principles of malice and injustice, but to his ignorance of David's having a right to the throne upon his father's death, and by the advice of his friends he took it: the sin of these men in murdering him is aggravated, in that they slew him in his own palace, upon his bed? in cold blood, and not in the field of battle, not being engaged in war with him; in his own palace, where he might justly think himself in safety; on his bed asleep, and so at an unawares, when insensible of danger, and not in a posture of defence; and now David argues from the lesser to the greater, that if the man that brought him the tidings of Saul's death had no reward given him for bringing what he thought would be reckoned good tidings, then much less would any be given them who had actually slain their master, and that in such a base and barbarous way; and if the above person, who only was a bringer of tidings, was taken and slain, then how much more did they deserve to die, who had been guilty of such a cruel and barbarous murder? shall I not therefore now require his blood of your hands, and take you away from the earth? avenge his blood on them, by putting them to death, out of the world, and from the land of the living, as men that deserved to live no longer on it.