Just like a chaste woman has got good reputation, similarly, a chaste tongue . . . chaste tongue means . . . chaste tongue and ear. Jihvādau. Our spiritual life begins from tongue. Jihvādau. Sevonmukhe hi jihvādau svayam eva sphuraty adaḥ. Ataḥ śrī-kṛṣṇa-nāmādi na bhaved grāhyam indriyaiḥ (CC Madhya 17.136). These senses—these mundane, blunt senses—they cannot receive or understand what is Kṛṣṇa, what is Kṛṣṇa's name, what is Kṛṣṇa's form, what is Kṛṣṇa's pastimes, what is Kṛṣṇa's paraphernalia—so many things Kṛṣṇa's . . . what is Kṛṣṇa's word. Na bhaved grāhyam indriyaiḥ. These senses cannot do it.
But when the one sense, the tongue, is engaged in devotional service . . . the tongue is engaged in devotional service means chant Hare Kṛṣṇa. This tongue is especially given to you. The dog, the cat cannot chant Hare Kṛṣṇa, but you can, because God has given you the opportunity. So just like chaste woman means he (she) is meant for her husband, similarly, chaste tongue means which is meant for chanting Hare Kṛṣṇa. That is chaste tongue. And tasting kṛṣṇa-prasādam.