Nathan the Prophet approaches King David at a critical moment of royal succession, using a carefully calculated strategy to provoke a reaction about Adonijah's sudden rise to power. His approach is highly sophisticated and notably different from how Bathsheba previously presented the crisis. Rather than making a direct accusation, Nathan poses a rhetorical question. He asks if the king himself authorized these events, speaking with a distinct tone of wonder and astonishment [רש״י, רד״ק, אברבנאל]. Although his words are initially phrased as a statement, the primary approach among commentators is that they function as an inquiry, asking for clarification [מצודת דוד, ביאור שטיינזלץ, רלב״ג].
This tone of astonishment serves two distinct interpretive purposes. On one hand, Nathan presents the unfolding events as if Adonijah's coronation was carried out under David's secret instructions. Because Adonijah is actively behaving like a king by offering sacrifices and gathering followers, Nathan acts as though David must have approved it. In this scenario, Nathan is merely complaining that the king chose to hide the decision and exclude him from the process [רד״ק, רלב״ג]. To make this act convincing, Nathan pretends to be completely unaware of David's earlier oath promising the throne to Solomon. He acts as if he has no objection to Adonijah taking power, expressing frustration only at being left in the dark [מלבי״ם].
On the other hand, the prophet's astonishment can be understood as a way to highlight the sheer severity of Adonijah's rebellion. By asking if the king authorized these actions, while knowing perfectly well that David never issued such a command, Nathan guides the king to an unavoidable conclusion. If David did not order this, it exposes just how audacious Adonijah has been in daring to act like a monarch and seize power without any royal permission [אברבנאל].