Tamal Krishna: Thirteen and fourteen: "One should hold one's body, neck and head erect in a straight line and stare steadily at the tip of the nose. Thus, with an unagitated, subdued mind, devoid of fear, completely free from sex life, one should meditate upon Me within the heart and make Me the ultimate goal of life (BG 6.13-14)."
Prabhupāda: This is the process. First of all you have to select a nice place, solitary place and you have to execute alone. Not that you go to a yoga class and pay your fees and make some gymnastic and come back home and do all nonsense. You see? Don't be entrapped by all these ridiculous things, you see? Simply… Such society, I can declare, is the society of the cheaters and the cheated. You see? Here is the practice. Here you can see. And spoken by the supreme authority, Kṛṣṇa. Is there any person better yogi than Kṛṣṇa?
Here is the authoritative statement. That you have to practice like this. Now, one should hold one's body, first of all you have to select your place, holy place, alone, and special seat. Then you have to sit straight like this. "One should hold one's body, neck and head erect." Straight line. This is the yoga process. These things help to concentrate the mind. That's all. But the real purpose of yoga is to keep Kṛṣṇa always within yourself. Here it is said, stated, that "One should hold one's body, neck and head erect in a straight line and stare steadily at the tip of the nose." Now here, you have to see. And if you close, meditation, you'll sleep. I have seen. So many so-called meditators, they're sleeping. (makes snoring sound) I've seen it. You see? Because as soon as you close your eyes it is natural that you'll feel sleepy, you see? Therefore, half-closed. You have to see. That is the process. You have to see the tip of your nose, two eyes. Thus with unagitated mind. This process will help your mind to be fixed up, unagitated mind, subdued mind, devoid of fear. Yes. Because you have to, generally the yogis they used to practice in jungle and if he's thinking of, "Some tiger is coming or not, what is that?" (laughter) You see? Or some snake is coming. Because you have to sit down alone in a jungle. You see. There are so many animals. Tigers, and deers, and snake. So therefore it is specially stated, "devoid of fear." The skin of deer is specially used in yoga-āsana because it has got some medical effect that snakes do not come. If you sit down on that particular skin, the snakes and reptiles will not come there. That is the purpose. You'll not be disturbed. Devoid of fear, completely free from sex life. You see. If you indulge in sex life, you cannot fix up your mind in anything. That is the effect of brahmacārī life. If you remain brahmacārī without sex life, then you can be determined.