Adam Clarke's Bible Commentary Verse 5. Thou hast shamed this day] Joab's speech to David on his immoderate grief for the death of his rebellious son is not only remarkable for the insolence of office, but also for good sense and firmness. Every man who candidly considers the state of the case, must allow that David acted imprudently at least; and that Joab's firm reproof was necessary to arouse him to a sense of his duty to his people. But still, in his manner, Joab had far exceeded the bonds of that reverence which a servant owes to his master, or a subject to his prince. Joab was a good soldier, but in every respect a bad man, and a dangerous subject.
John Gill's Bible Commentary Ver. 5. And Joab came into the house to the king , etc.] For by this time he was removed from the chamber over the gate to his own dwelling house or palace, where he continued the same doleful ditty as at first: and said, thou hast shamed this day the faces of all thy servants ; they cannot lift up their heads, and look any in the face, nor one another; but behave as if they had committed some very great fault, in fighting with the rebels, and beating them: which this day have saved thy life, and the lives of thy sons, and of thy daughters, and the lives of thy wives
, and the lives of thy concubines ; which in all probability would have been taken away if the victory had been on the side of Absalom.
Matthew Henry Commentary
Verses 1-8 - To continue to lament for so bad a son as Absalom, was very unwise, an very unworthy. Joab censures David, but not with proper respect an deference to his sovereign. A plain case may be fairly pleaded with those above us, and they may be reproved for what they do amiss, but it must not be with rudeness and insolence. Yet David took the reproof an the counsel, prudently and mildly. Timely giving way, usually prevent the ill effects of mistaken measures.
Original Hebrew ויבא935 יואב3097 אל413 המלך4428 הבית1004 ויאמר559 הבשׁת3001 היום3117 את853 פני6440 כל3605 עבדיך5650 הממלטים4422 את853 נפשׁך5315 היום3117 ואת853 נפשׁ5315 בניך1121 ובנתיך1323 ונפשׁ5315 נשׁיך802 ונפשׁ5315 פלגשׁיך׃6370