1 Kings 2:5

"Moreover, you also know what Joab the son of Zeruiah did to me, how he dealt with the two commanders of the armies of Israel, Abner the son of Ner, and Amasa the son of Jether, whom he killed, avenging in time of peace for blood that had been shed in war, and putting the blood of war on the belt around his waist and on the sandals on his feet.