But 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; he might see the sword drop out of the scabbard, and Joab take it up, which he supposed he did in order to put it into its sheath again, having no suspicion of his wicked design, and therefore not at all upon his guard to prevent it:
so he smote him therewith in the fifth [rib];
in the same place where Abner smote Asahel, and Joab Abner; (See Gill on 2 Samuel 2:23) and (See Gill on 2 Samuel 3:27): he must strike him, as some observe, on the left side, because he was embracing him; and the stroke must be deadly, because he struck him in the pericardium, which surrounds the heart round with water, to refrigerate it; for the lower part of the heart reaches to the fifth rib; see ( John 19:34 ) F21:
and shed out his bowels to the ground;
which fell out through the incision made by the sword:
and struck him not again:
he gave him such a home thrust, there was no need to repeat it, he dispatched him at once:
and he died;
and thus, though he was pardoned by David, and promoted to honour by him, yet the providence of God would not suffer him to go unpunished for joining with Absalom in an unnatural rebellion against his uncle:
so Joab and Abishai his brother pursued after Sheba the son of Bichri:
for Amasa being slain, Joab without any ceremony reassumed his post as general, and, with his brother Abishai under him, made all the haste they could in pursuit of the rebel.
F21 Weemse's Portrait of Man, p. 25.