II Samuel 3:36 And all the people took notice of it, and it pleased them: as whatsoever the king did pleased all the people.
Joab has killed Abner. Abner had been the leader of the opposition to David. He had also killed one of Joab’s brothers, a nephew to David. David does not agree with Joab in how he killed Abner.
I am pretty sure that Joab expected David to be pleased. David didn’t just want people dying. He was ready to heal the nation.
It is hard to please everyone. The leader isn’t allowed to or shouldn’t be taking vengeance. His compassion and forgiveness wins the hearts of the people.
I should learn to forgive. I should learn not to seek vengeance. I should learn to trust that God will protect my position and that I do not have to do so!