Can a President De Classify Thick for One Person?

The constitution gives the president, i believe, the right to classify or de classify anything. Can a president de classify something by his actions, without words and without documents? For example, let's say i walked into the the oval office and the president said, you don't have clearance. Would just e classifie, for the people in the room? Or is the fact that it's being in a generic way i prove that it's bent classified? But i feel like yes. And i feel like even if he had, that's a good question, if the people who packed the boxes did not have top secret clearance. If they didn't, then isn't that declassifying it