Why was Paul not allowed to tell what he saw and heard in paradise?
Paul was not allowed to repeat what he saw and heard because God permitted him to see and hear but told him he could not repeat it and had to keep it to himself. Scripture says the words were unspeakable and not lawful for a man to utter.
Les explains that Paul had a full exposure to heaven's glories, heard magnificent things, and was caught up into paradise, where he heard unspeakable words which it is not permitted or lawful for a man to utter. God said, in effect, that He was letting Paul see and hear, but Paul could not repeat it and had to keep it to himself. Paul therefore would not glory in the experience but spoke of his infirmities, so no one would think of him above what they saw or heard.
How that he was caught up into paradise, and heard unspeakable words, which it is not lawful for a man to utter.