Everyone in this material world is controlled by the senses. That is material world. We cannot control our senses. The tongue is dry and dictating, "Take a cigarette, take a cigarette," and immediately I begin to smoke. That means I am dictated by the tongue. Then tongue, then belly. The belly is filled up, and still, there is some nice foodstuff—"All right, let me eat it." Control, cannot control. And then genital. That, we know very well, we cannot control. This straight line: tongue, belly and the genitals. Therefore one should control the tongue first.
That is spiritual life beginning, controlling the tongue. Sevonmukhe hi jihvādau (Bhakti-rasāmṛta-sindhu 1.2.234). The controlling of the senses begins from the tongue. If you allow the tongue to eat anything in the restaurant or anywhere, then you cannot become the jitendriya. And if you can control the tongue—"My dear tongue, I shall not give you any food which is not offered to Kṛṣṇa, kṛṣṇa prasādam"—then the tongue is controlled. And kṛṣṇa-prasādam means patraṁ puṣpaṁ phalaṁ toyaṁ yo me bhaktyā prayacchati (BG 9.26). If you want to offer Kṛṣṇa something, we must know what Kṛṣṇa wants to eat. Just like if you call a friend, you ask him, "My dear friend, what do you like to eat?" Then it is etiquette.