The woman asks this rhetorical question to rebuke David for how he has treated Absalom. This question can be written as a statement. Alternate translation: "What you have just said proved that you did wrong." (See: [[rc://en/ta/man/translate/figs-rquestion]])
The woman compares the king to someone who is guilty to suggest that he is guilty without saying it directly. Alternate translation: "the king has declared himself guilty"