'When one understands the True, then one declares the True. One who does not understand it, does not declare the True. Only he who understands it, declares the True. This understanding, however, we must desire to understand.' 'Sir, I desire to understand it.'

In plain words: Only a person who understands the Truth can speak the Truth. Without understanding, you cannot speak it. So we must want to understand. Narada says he wants to understand.