1 Kings 2:8

Behold thou hast with thee Shimei, &c., which cursed me with a grievous curse “David,” says Delaney, “when he was importuned to punish Shimei, (2 Samuel 16:9; 2 Samuel 19:21,) imitated the mercy of God, who waits that he may be gracious. Had he copied after any lower pattern, he had not spared Shimei, in the very instant of passion and provocation; nor would he afterward have forgiven him, in the fulness of prosperity and power. He very well knew how much the remission of personal injuries became the kingly character, and, therefore, he gave Shimei his life, and confirmed the grant by an oath. But then it must be remembered, that the obligation of the oath was purely personal; for so he himself explains it, saying, I sware unto him by the Lord, I will not put thee to death by the sword. And, therefore, though David was bound, Solomon was at full liberty to vindicate the majesty of kings, in chastising this high insult upon his father in such a manner as he thought fit: nor was there any danger of doing this to excess, when the chastisement was deferred to the calm and cool season of dispassionate justice; when neither passion nor personal resentment could inflame the vengeance. David well knew how much it became the piety of his character to submit himself and his concerns to the divine disposal, throughout the whole course of his life; but could he, for this reason, wholly renounce the interest of justice? Or, if he could, he very well knew how dangerous an example it might be to his successors, to suffer such injuries and insults upon majesty to pass unpunished: and, therefore, when he had acted up to the piety and dignity of his own character, he very wisely admonished his son to act up to the wisdom of his.”