And while they were at the great stone in Gibeon, Amasa joined them. Now Joab was dressed in military attire, with a dagger strapped to his belt. And as he stepped forward, he slipped the dagger from its sheath.
Jewish Publication Society of America Version (JPS1917) - 2 Samuel 20:8 >When they were at the great stone which is in Gibeon, Amasa came to meet them. And Joab was girded with his apparel of war that he had put on, and thereon was a girdle with a sword fastened upon his loins in the sheath thereof; and as he went forth it fell out.