It is not necessary to explain to the public what the Truth has made vague about His creation and has limited to His own, for this is the utmost bad etiquette. I do not think that Al-Tirmidhi intended with this question to ask for explanation and clarification of its meaning. Rather, he intended to test the questioner that if he is among the people of God, he should not explain it, but if he explained it, then he would have received it. From someone who received it from him by mistake due to evidence of his situation and intelligence in it. As for the people of God, they have divine etiquette that prevents them from covering up what God has revealed or revealing what God has covered.