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.

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,

Joab asked Amasa how he was, and laid hold of his bear with his right hand to kiss him. And as Amasa took no heed of the sword in Joab's hand, he smote him with ...

Amasa took no heed to the sword that [was] in Joab's hand, &c.] In his left hand, for with his right hand he took him by the beard.

New International Version 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 ...

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 him not ...

The king ordered Amasa, “Muster the men of Judah for me in three days; then report in.” Amasa went to carry out his orders, but he was late reporting back.

David Guzik commentary on 2 Samuel 20 describes how David returns to Jerusalem, but has an opponent in Sheba, who gets killed by Joab.

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.

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...