2Sa 16:9-10, 9 Then Abishai the son of Zeruiah said to the king, “Why should this dead dog curse my lord the king? Please, let me go over and take off his head!” 10 But the king said, “What have I to do with you, you sons of Zeruiah? So let him curse, because the LORD has said to him, ‘Curse David.’ Who then shall say, ‘Why have you done so?’ “
Abishai, one of David’s top general and one he would trust with his own life stepped in to maintain David’s honor. Shimei as it looks was not a big threat to David physically but his reputation. Abishai could not stand to see the king being slandered by lies and was ready silence Shimei for good, but David would not let him. He felt that he deserved it and pictured it as from the hands of God.
This is close to the story of the sons of thunder. These disciples of Christ in their zeal for His honor would have commanded fire from heaven on the town that affronted Jesus (Luk 9:55). Both David and Jesus would not permit the request of these men. Both refused to use their office and power to do harm even against those who would have deserved their wrath. They were indeed slow to wrath.
They both teach us a valuable lesson, “A humble tender spirit will turn reproaches into reproofs, and so get good by them, instead of being provoked by them” (Matthew Henry). And remember this, Jesus “though He was a Son, yet He learned obedience by the things which He suffered.” (Heb 5:8).