6 It happened, while there was war between the house of Saul and the house of David, that Abner made himself strong in the house of Saul.
7 Now Saul had a concubine, whose name was Rizpah, the daughter of Aiah: and Ishbosheth said to Abner, “Why have you gone in to my father’s concubine?” 8 Then was Abner very angry for the words of Ishbosheth, and said, “Am I a dog’s head that belongs to Judah? Today I show kindness to the house of Saul your father, to his brothers, and to his friends, and have not delivered you into the hand of David; and yet you charge me this day with a fault concerning this woman! 9 God do so to Abner, and more also, if, as Yahweh has sworn to David, I don’t do even so to him; 10 to transfer the kingdom from the house of Saul, and to set up the throne of David over Israel and over Judah, from Dan even to Beersheba.” 11 He could not answer Abner another word, because he feared him. 12 Abner sent messengers to David on his behalf, saying, “Whose is the land?” and saying, “Make your alliance with me, and behold, my hand shall be with you, to bring all Israel around to you.”
Matthew Henry's Commentary on 2 Samuel 3:6-12
Commentary on 2 Samuel 3:1-6
(Read 2 Samuel 3:1-6)
The length of this war tried the faith and patience of David, and made his settlement at last the more welcome. The contest between grace and corruption in the hearts of believers, may fitly be compared to this warfare. There is a long war between them, the flesh lusting against the spirit, and the spirit against the flesh; but as the work of holiness is carried on, corruption, like the house of Saul, grows weaker and weaker; while grace, like the house of David, grows stronger and stronger.
Commentary on 2 Samuel 3:7-21
(Read 2 Samuel 3:7-21)
Many, like Abner, are not above committing base crimes, who are too proud to bear reproof, or even the suspicion of being guilty. While men go on in sin, and apparently without concern, they are often conscious that they are fighting against God. Many mean to serve their own purposes; and will betray those who trust them, when they can get any advantage. Yet the Lord serves his own designs, even by those who are thus actuated by revenge, ambition, or lust; but as they intend not to honour him, in the end they will be thrown aside with contempt. There was real generosity both to Michal and to the memory of Saul, in David's receiving the former, remembering probably how once he owed his life to her affection, and knowing that she was separated from him partly by her father's authority. Let no man set his heart on that which he is not entitled to. If any disagreement has separated husband and wife, as they expect the blessing of God, let them be reconciled, and live together in love.