2 Samuel 16:5-7, 9-10

When King David came to Bahurim, behold, there came out from there a man of the family of the house of Saul whose name was Shimei, the son of Gera; he came out cursing continually as he came. He threw stones at David and at all the servants of King David; and all the people and all the mighty men were at his right hand and at his left. Thus Shimei said when he cursed, “Get out, get out, you man of bloodshed, and worthless fellow!

Then Abishai the son of Zeruiah said to the king, “Why should this dead dog curse my lord the king? Let me go over now and cut off his head.” But the king said, “What have I to do with you, O sons of Zeruiah? If he curses, and if the LORD has told him, ‘Curse David,’ then who shall say, ‘Why have you done so?’ ”