I personally like the prophet Nathan because he used what I would call indirect apologetics to correct David. Here is the example that I am thinking of:
The LORD sent Nathan to David, and when he came to him, he said: "Judge this case for me! In a certain town there were two men, one rich, the other poor. The rich man had flocks and herds in great numbers. But the poor man had nothing at all except one little ewe lamb that he had bought. He nourished her, and she grew up with him and his children. She shared the little food he had and drank from his cup and slept in his bosom. She was like a daughter to him.
Now, the rich man received a visitor, but he would not take from his own flocks and herds to prepare a meal for the wayfarer who had come to him. Instead he took the poor man's ewe lamb and made a meal of it for his visitor."
David grew very angry with that man and said to Nathan: "As the LORD lives, the man who has done this merits death!
He shall restore the ewe lamb fourfold because he has done this and has had no pity."
Then Nathan said to David: "You are the man! (2 Samuel 12:1-9)
If you don't understand what Nathan is talking about go read 2 Samuel 11