1 Kings 2:4-5

4That the LORD may establish his word which he spake concerning me, saying, If thy children take heed to their way, to walk before me in truth with all their heart and with all their soul, there shall not fail thee (said he) a man on the throne of Israel.

5Moreover thou knowest also what Joab the son of Zeruiah did unto me, even what he did to the two captains of the hosts of Israel, unto Abner the son of Ner, and unto Amasa the son of Jether, whom he slew, and shed the blood of war in peace, and put the blood of war upon his girdle that was about his loins, and in his shoes that were on his feet.