The answer is: Nathan

2 Sam 12:1 - David sent Uriah into battle to be killed so he could take Bathsheba as his wife

In a gripping narrative of human emotion and consequence, Nathan steps onto the scene in 2 Samuel 12—a true masterclass in prophetic confrontation! Picture David in his palace, basking in the kingly comforts he had amassed, when Nathan arrives, not with thunderous condemnation but through a meticulously crafted parable. He tells the story of a rich man who steals a poor man's beloved lamb—a little sheep with a fond attachment. David, unaware he’s just become the unwitting protagonist of his moral test, unconsciously calls for the wealthy man’s punishment. This is the moment Nathan reveals the surely devastating words, “You are the man!”

It’s a remarkable illustration of how the truth sometimes gets revealed in cleverly anticipated ways, and it's fascinating to note this is a continuation of God's mercy—the God who doesn’t simply smite, but rather sends Nathan as a physician to heal David’s moral wounds. David, unlike many leaders before him who had the mantle of pride, genuinely repents, setting a precedent for recognizing faults publicly.

As intriguing trivia, this isn't the only encounter where God sends prophets for reproof; Amos and Hosea come to mind. Moreover, seeing David's journey illuminates the messy reality of human choices and divine grace, resonating well throughout the arts, literature, and contemporary discussions around ethics. David's saga is not just a moment frozen in time but a living narrative enticing engagement and reflection through generations.