Now while there was war between the house of Saul and the house of David, Abner the son of Ner ruled the house of Saul.

And it cometh to pass, in the war being between the house of Saul and the house of David, that Abner hath been strengthening himself in the house of Saul,

Now while there was war between Saul's people and David's people, Abner was making himself strong among the supporters of Saul.

And it came to pass, while there was war between the house of Saul and the house of David, that Abner showed himself strong in the house of Saul.

Then, while there was a battle between the house of Saul and the house of David, Abner, the son of Ner, was reigning over the house of Saul.

Render, "And it came to pass, while the war between the house of Saul and the house of David lasted, that Abner assisted the house of Saul."

Abner made himself strong - This strengthening of himself, and going in to the late king's concubine, were most evident proofs that he wished to seize upon the government. See 1-Kings 2:21, 1-Kings 2:22; 1-Kings 12:8; 1-Kings 16:21.

And it came to pass, while there was war between the house of Saul and the house of David,.... As long as that continued, as it did until the following quarrel happened between Ishbosheth and Abner:
that Abner made himself strong for the house of Saul; or was strongly in the interest of that house, and used his utmost endeavours to support and confirm it.

ABNER REVOLTS TO DAVID. (2-Samuel 3:6-12)
Abner made himself strong for the house of Saul--In the East, the wives and concubines of a king are the property of his successor to this extent, that for a private person to aspire to marry one of them would be considered a virtual advance of pretensions to the crown (see 1-Kings 2:17). It is not clear whether the accusation against Abner was well or ill founded. But he resented the charge as an indignity, and, impelled by revenge, determined to transfer all the weight of his influence to the opposite party. He evidently set a full value on his services, and seems to have lorded it over his weak nephew in a haughty, overbearing manner.

Decline of the House of Saul. - 2-Samuel 3:6-11. Abner's quarrel with Ishbosheth. - During the war between the house of Saul and the house of David, Abner adhered firmly to the house of Saul, but he appropriated one of Saul's concubines to himself. When Ishbosheth charged him with this, he fell into so violent a rage, that he at once announced to Ishbosheth his intention to hand over the kingdom to David. Abner had certainly perceived the utter incapacity of Ishbosheth for a very long time, if not from the very outset, and had probably made him king after the death of Saul, merely that he might save himself from the necessity of submitting to David, and might be able to rule in Ishbosheth's name, and possibly succeed in paving his own way to the throne. His appropriation of the concubine of the deceased monarch was at any rate a proof, according to Israelitish notions, and in fact those generally prevalent in the East, that he was aiming at the throne (vid., 2-Samuel 16:21; 1-Kings 2:21). But it may gradually have become obvious to him, that the house of Saul could not possibly retain the government in opposition to David; and this may have led to his determination to persuade all the Israelites to acknowledge David, and thereby to secure for himself an influential post under his government. This will explain in a very simple manner Abner's falling away from Ishbosheth and going over to David.

Strong - He used all his endeavours to support Saul's house: which is mentioned, to shew the reason of his deep resentment of the following aspersion.