10 Amasa was not on his guard against the dagger in Joab's hand, and Joab plunged it into his belly, and his intestines spilled out on the ground. Without being stabbed again, Amasa died. Then Joab and his brother Abishai pursued Sheba son of Bikri.
10 But Amasa took no heed to the sword that was in Joab's hand: so he smote him therewith in the fifth rib, and shed out his bowels to the ground, and struck
10 But Amasa did not observe the sword that was in Joab's hand. So Joab struck him with it in the stomach and spilled his entrails to the ground without striking a second blow, and he died. Then Joab and Abishai his brother pursued Sheba the son of Bichri.
10 Amasa didn't notice the sword in Joab's other hand. Joab stuck him in the belly and his guts spilled to the ground. A second blow wasn't needed; he was dead. Then Joab and his brother Abishai continued to chase Sheba son of Bicri.
10 But Amasa did not notice the sword that was in Joab's hand. And he struck him with it in the stomach, and his entrails poured out on the ground; and he did not strike him again. Thus he died. Then Joab and Abishai his brother pursued Sheba the son of Bichri.
10 Amasa didn't notice the dagger in his left hand, and Joab stabbed him in the stomach with it so that his insides gushed out onto the ground. Joab did not need to strike again, and Amasa soon died. Joab and his brother Abishai left him lying there and continued after Sheba.
Matthew Henry's Commentary on 2 Samuel 20:10
Commentary on 2 Samuel 20:4-13
(Read 2 Samuel 20:4-13)
Joab barbarously murdered Amasa. The more plot there is in a sin, the worse it is. Joab contentedly sacrificed the interest both of the king and the kingdom to his personal revenge. But one would wonder with what face a murderer could pursue a traitor; and how, under such a load of guilt, he had courage to enter upon danger: his conscience was seared.