Verse 6. - Do therefore according to thy wisdom [cf. Proverbs 20:26. It needed great discretion in exacting the punishment of death in the case of one who was so powerful, who had such influence with the army and the people, whose crimes had been passed over for so long a time, to whom David was so much indebted - Joab had partly won and had twice preserved for him his crown - and to whom he was allied by ties of blood. To act precipitately or unwisely might provoke a revolution], and let not his hoar head [see on ver. 9. Joab, though David's nephew, could not have been much his junior, and David was now seventy] go down to the grave in peace. [He must die a violent, not a natural death, as Corn. a Lap. This expression, no doubt, looks vindictive, but that is solely because we forget the character of the Old Testament dispensation (as one of temporal rewards and punishments. See the "Expositor," vol. 3. p. 114), the position of David as king (as the authorized dispenser of punishments, and as responsible to God for dispensing them without fear or favour), and the principles of the Mosaic code (as a lex talionis, demanding blood for blood, and requiring the magistrates and people to purge themselves of the guilt of blood by demanding "the blood of him that shed it"). Let these considerations be borne in mind, and there is absolutely no warrant for charging David with malevolence. Wordsworth lays stress on the fact that Joab had not repented of his crimes. But we need have recourse to no such suppositions. The Jewish law afforded no place of repentance to the murderer. No amount of contrition would cleanse the land of blood. The temporal penalty must be paid. In the case of David himself, it was only commuted by special revelation (2 Samuel 12:10, 13, 14), not remitted.

2:5-11 These dying counsels concerning Joab and Shimei, did not come from personal anger, but for the security of Solomon's throne, which was the murders he had committed, but would readily repeat them to carry any purpose; though long reprieved, he shall be reckoned with at last. Time does not wear out the guilt of any sin, particularly of murder. Concerning Shimei, Hold him not guiltless; do not think him any true friend to thee, or thy government, or fit to be trusted; he has no less malice now than he had then. David's dying sentiments are recorded, as delivered under the influence of the Holy Ghost,Do therefore according to thy wisdom,.... Which though young began to appear in him, even in the life of his father; he therefore exhorts him to use the wisdom he had, and take the first and fittest opportunity to cut him off for his former murders and late treason, as a dangerous man to his government and the peace of it:

and let not his hoary head go down to the grave in peace; that is, let him not die a natural, but a violent death; and let not his grey hairs be any argument for sparing him, or any reason for delaying the taking of him off, because he would in course die quickly; for he must be now an old man, as old as David, or perhaps older; since he had been his general forty years, even all the time of his reign; see 2 Samuel 2:13.