Just like if you have got some disease in the eyes, you apply medicine, and when it is clear, you can see clearly everything; similarly, with these blunt senses, we cannot understand what is Kṛṣṇa. Sevonmukhe hi jihvādau svayam eva sphuraty adaḥ (Brs. 1.2.234). As śrī-kṛṣṇasya nāmādau, Kṛṣṇa's name, form, quality, etc., is not understand by these blunt senses, so how it is to be done? Now, sevonmukhe hi jihvādau. Again jihvādau, beginning from the tongue, controlling the tongue. Just see it is something peculiar, that you have to understand Kṛṣṇa by controlling the tongue? This is something wonderful. How is that? I have to control my tongue to understand Kṛṣṇa? But it is, the śāstra injunction is there: sevonmukhe hi jihvādau. Jihvā means tongue. So in order to see Kṛṣṇa, in order to understand Kṛṣṇa, the first business is to control your tongue. Therefore we say, don't take meat, don't take liquor. Because it is controlling the tongue. The tongue is the most strong enemy as sense, as perverted sense. And these rascals they say, "No, you can eat whatever you like. It has nothing to do with religion." But Vedic śāstra says, "You rascal, first of all control your tongue. Then you can understand what is God."
So this is called Vedic injunction—perfect. If you control your tongue, then you control your belly, then you control your genital.