1 Kings 2:5

“ Moreover you know also what Joab the son of Zeruiah did to me, even what he did to the two captains of the hosts of Israel, to Abner the son of Ner, and to Amasa the son of Jether, whom he slew, and shed the blood of war in peace, and put the blood of war on his girdle that was about his loins, and in his shoes that were on his feet.”

David then went on to give advice about individual matters where he felt that his experience could be a guide to his son. David was well aware that Joab had supported Adonijah, and he knew perfectly well what Joab was capable of. He feared that a man who could catch out two experienced generals and kill them in cold blood would think little of doing the same to a less experienced king who was getting in the way of his ambitions. And he knew that while he had himself known that he could always count on Joab’s loyalty, because there had been a bond forged between them by the hardship which they had suffered together, he could not be so confident that Solomon would be able to do so, especially as Joab would know that by supporting Adonijah he had, as far as Solomon was concerned, almost certainly said goodbye to any ambitions for the future he might have had. David was well aware that Joab, found in that situation, would be a very dangerous man, a man who could stoop to anything.

But David, in warning Solomon, would not want to raise the spectre of Adonijah’s actions again, for Adonijah was his son, and he wanted peace between his sons, and so he chose a different tack. He reminded Solomon of what Joab had done to David himself in the past, when he had slain two men in a way which had brought part of the blame on David. There were indeed still men, and Shimei was probably one, who believed that David himself had been responsible in some way for Abner’s death, while others, especially of the house of Judah, no doubt held Amasa’s death against him. And it was all because of Joab’s willingness to spill blood so easily.

Of course Joab had had a good excuse in both cases. In the case of Abner he could justifiably claim that he was avenging the shedding of the blood of his brother. And that was unquestionably true. He was strictly within his rights to slay the killer of his brother when that killer had not sought ‘refuge’ and a fair trial. Especially when the killing had taken place in a civil war provoked by Abner. In the case of Amasa he had no doubt claimed with some justification that Amasa had been acting treacherously. And there can be no doubt that Amasa’s failure to do his duty had merited severe punishment. But in both cases, as both he and David well knew, he had acted over and above what he had known David wanted him to do, and partly did it because the two men stood in the way of his ambition to continue as commander-in-chief of all Israel. Both men had come openly to make peace with David and Joab, and Joab’s response had been to strike them down. He had ‘shed the blood of war in peace’ without trial. Technically he had been justified (compare Gideon’s act in Judges 8:18-21), but, as Joab had been aware, both men had been under David’s protection, and the result was that Joab’s actions had thus brought dishonour on David and had revealed what kind of a man Joab, was. And the result was that the girdle that held his sword was seen as stained with blood that could never be washed off, as were the shoes on his feet. He was a man of blood. He was a man who shed blood and trod blood wherever he went, and that could not be good news for Solomon. Thus the warning.