12 Amasa was lying in a pool of blood in the middle of the road; the man realized that the whole army was going to stop and take a look, so he pulled Amasa's corpse off the road into the field and threw a blanket over him so it wouldn't collect spectators.
Matthew Henry's Commentary on 2 Samuel 20:12
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.