2 Samuel 20:8

Amasa went before them As their commander-in-chief. Having gathered some forces, and given due orders for the rest to follow him, he returned to Jerusalem, and by the king's command went after those mentioned 2 Samuel 20:7, and being come up to them at the place where they waited for him, he put himself at the head of Joab's men, and the Cherethites and the Pelethites, and such as he had brought along with him, and marched before them as their general. Joab's garment was girded unto him After the manner of travellers and soldiers: for he had now no armour on, but only such a garment as soldiers wore, closely girt to him. Upon it a girdle with a sword A belt, in which a sword hung by his side. As he went forth To meet and salute Amasa, who was coming toward him to do him honour; it fell out Having, probably, been designedly so hung by Joab, that upon some particular motion of his body, it might drop out of the sheath, and he might take it up without awaking Amasa's suspicion.