2 Samuel 3:21
“And Abner said unto David, I will arise and go, and will gather all Israel unto my lord the king, that they may make a league with thee, and that thou mayest reign over all that thine heart desireth. And David sent Abner away; and he went in peace.”
And Abner also spake in the ears of Benjamin: and Abner went also to speak in the ears of David in Hebron all that seemed good to Israel, and that seemed good to the whole house of Benjamin.
So Abner came to David to Hebron, and twenty men with him. And David made Abner and the men that were with him a feast.
And Abner said unto David, I will arise and go, and will gather all Israel unto my lord the king, that they may make a league with thee, and that thou mayest reign over all that thine heart desireth. And David sent Abner away; and he went in peace.
And, behold, the servants of David and Joab came from pursuing a troop, and brought in a great spoil with them: but Abner was not with David in Hebron; for he had sent him away, and he was gone in peace.
When Joab and all the host that was with him were come, they told Joab, saying, Abner the son of Ner came to the king, and he hath sent him away, and he is gone in peace.
Counter-Arguments
The strongest case that this verse does not belong in this theme.

Cross-References
“Now therefore, O king, come down according to all the desire of thy soul to come down; and our part shall be to deliver him into the king’s hand.”
“And Abner sent messengers to David on his behalf, saying, Whose is the land? saying also, Make thy league with me, and, behold, my hand shall be with thee, to bring about all Israel unto thee.”
“And Abner sent messengers to David on his behalf, saying, Whose is the land? saying also, Make thy league with me, and, behold, my hand shall be with thee, to bring about all Israel unto thee.”
“And made him king over Gilead, and over the Ashurites, and over Jezreel, and over Ephraim, and over Benjamin, and over all Israel.”
“To translate the kingdom from the house of Saul, and to set up the throne of David over Israel and over Judah, from Dan even to Beer–sheba.”