Tongue is the Priniciple Sense

Of all the senses, the tongue is considered to be the principal sense. So tongue, if the tongue is trained, or the tongue is spiritualized, then naturally all the senses become spiritualized. So jihvadau. So our training is the tongue training. Train it chanting Hare Krsna and let it taste Krsna prasadam. Then what will be? The all other senses... There are five senses for acquiring knowledge, five senses for acting. Everything will be controlled.
(Talk, Initiation Lecture, and Ten Offenses Lecture -- Los Angeles, December 1, 1968)