2Sam 3:20

“He had bound the people to himself freely in doing his duty; first, when during the division among the people he preferred to live like an exile at Hebron rather than to reign at Jerusalem; next, when he showed that he loved valor even in an enemy. He had also thought that justice should be shown to those who had borne arms against himself the same as to his own men. Again, he admired Abner, the bravest champion of the opposing side, while he was their leader and was yet waging war. Nor did he despise Abner when suing for peace, but honored him by a banquet. When killed by treachery, David mourned and wept for him. He followed him and honored his obsequies and evinced his good faith in desiring vengeance for the murder; for he handed on that duty to his son in the charge that he gave him, being anxious rather that the death of an innocent man should not be left unavenged than that any one should mourn for his own.”