I may not tarry thus with thee - He had nothing to say in vindication of the purpose he had formed.
Thrust them through the heart of Absalom - He was determined to make sure work, and therefore he pierced his heart.
Joab should have obeyed the king’s commandment: and yet the safety of the state required the sacrifice of Absalom. But independently of this, his life was quadruply forfeited to the law: -
1. In having murdered his brother Amnon.
2. In having excited an insurrection in the state.
3. In having taken up arms against his own father, Deu 21:18, Deu 21:21.
4. In having lain with his father’s concubines, Lev 18:29.
Long ago he should have died by the hand of justice; and now all his crimes are visited on him in his last act of rebellion. Yet, in the present circumstances, Joab’s act was base and disloyal, and a cowardly murder.