Flavius Josephus, Antiquities of the Jews
William Whiston, A.M., Ed.

[31] When David had sent Abner away, Joab, the of his army, came immediately to Hebron; he had understood that Abner had been with David, and had parted with him a little before under leagues and agreements that the government should be delivered up to David, he feared lest David should place Abner, who had assisted him to gain the kingdom, in the first rank of dignity, especially since he was a shrewd man in other respects, in understanding affairs, and in managing them artfully, as proper seasons should require, and that he should himself be put lower, and be deprived of the command of the army; so he took a knavish and a wicked course. In the first place, he endeavored to calumniate Abner to the king, exhorting him to have a care of him, and not to give attention to what he had engaged to do for him, because all he did tended to confirm the government to Saul's son; that he came to him deceitfully and with guile, and was gone away in hopes of gaining his purpose by this management: but when he could not thus persuade David, nor saw him at all exasperated, he betook himself to a project bolder than the former: - he determined to kill Abner; and in order thereto, he sent some messengers after him, to whom he gave in charge, that when they should overtake him they should recall him in David's name, and tell him that he had somewhat to say to him about his affairs, which he had not remembered to speak of when he was with him. Now when Abner heard what the messengers said, (for they overtook him in a certain place called Besira, which was distant from Hebron twenty furlongs,) he suspected none of the mischief which was befalling him, and came back. Hereupon Joab met him in the gate, and received him in the kindest manner, as if he were Abner's most benevolent acquaintance and friend; for such as undertake the vilest actions, in order to prevent the suspicion of any private mischief intended, do frequently make the greatest pretenses to what really good men sincerely do. So he took him aside from his own followers, as if he would speak with him in private, and brought him into a void place of the gate, having himself nobody with him but his brother Abishai; then he drew his sword, and smote him in the groin; upon which Abner died by this treachery of Joab, which, as he said himself, was in the way of punishment for his brother Asahel, whom Abner smote and slew as he was pursuing after him in the battle of Hebron, but as the truth was, out of his fear of losing his command of the army, and his dignity with the king, and lest he should be deprived of those advantages, and Abner should obtain the first rank in David's court. By these examples any one may learn how many and how great instances of wickedness men will venture upon for the sake of getting money and authority, and that they may not fail of either of them; for as when they are desirous of obtaining the same, they acquire them by ten thousand evil practices; so when they are afraid of losing them, they get them confirmed to them by practices much worse than the former, as if no other calamity so terrible could befall them as the failure of acquiring so exalted an authority; and when they have acquired it, and by long custom found the sweetness of it, the losing it again: and since this last would be the heaviest of all afflictions they all of them contrive and venture upon the most difficult actions, out of the fear of losing the same. But let it suffice that I have made these short reflections upon that subject.