1 Kings 2:5

Moreover, thou knowest also what Joab, the son of Zeruiah, did to me, since he, with his strange influence in Israel, often acted counter to the wishes of the king, and 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, in willful and malicious murder, and shed the blood of war in peace, and put the blood of war upon his girdle that was about his loins, 2 Samuel 3:27; 2 Samuel 20:8, and in his shoes that were on his feet, these articles of apparel being named as those of a warrior, the former serving to hold up the sheath of the sword, the latter for marching. Joab had soiled with innocent blood the very insignia of his rank and dignity as general and soldier.