1 Kings 2:5

Now you also know what Joab the son of Zeruiah [my sister] did to me, and what he did to the two commanders of the armies of Israel, to Abner the son of Ner and to Amasa the son of Jether, [both of] whom he murdered; ^[b]avenging the blood of war in [a time of] peace. And he put the [innocent] blood of war [of Abner and Amasa] on his ^[c]belt that was around his ^[d]waist, and on his sandals on his feet.