 Hence, Amasa was a nephew of David, and cousin of Joab, David's military commander, as well as a cousin of Absalom, David's son.David calls him "my bone and my flesh" ().Amasa's father was Jether (, ) who was also called Ithra ()

When Absalom rebelled against David and won over the tribes of Israel (), he appointed Amasa as commander over the army, in effect replacing Joab, who had served as commander for David.