Bible Verses About Shoes: (Having blood on,) of being engaged in war and slaughter

Moreover, you know what Joab son of Zeruiah did to me—what he did to Abner son of Ner and Amasa son of Jether, the two commanders of the armies of Israel. He killed them in peacetime to avenge the blood of war. He stained with the blood of war the belt around his waist and the sandals on his feet.