1 Kings 2:5

To me — That is, against me; in what he did against Abner and Amasa: whose death was a great injury to David, as it was a breach of his laws and peace; a contempt of his person and government; a pernicious example to his subjects, and a great scandal to him, as if Joab had been only David's instrument, to affect what he secretly designed. And shed — He slew them as if they had been in the state of war, when there was not only a cessation of arms, but also a treaty of peace. Put the blood — This is added to note his impenitency, that although by his perfidious manner of killing them when he pretended to embrace them, he stained his own garments with their blood, yet he was not ashamed of it, but gloried in it, and marched boldly along with the army, with the same girdle and shoes which were sprinkled with their blood.