Senses cannot be artificially controlled; they become purified only when engaged in Krishna's service.Listen — Srila Prabhupada Uvaca
Bhagavad-gītā 4.26 — April 15, 1974, Bombay 740415BG-BOMBAY [37:28 Minutes] Bg-04.26_740415BG-BOMBAY Pradyumna: Translation: "Some of them sacrifice the hearing process and the senses in the fire of the controlled mind, and others sacrifice the objects of the senses, such as sound, in the fire of sacrifice." Prabhupāda: Read the purport. Pradyumna: "The four divisions of human life, namely the brahmacārī, the gṛhastha, the vānaprastha and sannyāsī, are all meant to help men become perfect yogīs, or transcendentalists. Since human life is not meant for our enjoying sense gratification like the animals, the four orders of human life are so arranged that one may become perfect in spiritual life. The brahmacārīs, or students under the care of a bona fide spiritual master, control the mind by abstaining from sense gratification. They are referred to in this verse as sacrificing the hearing process and the senses in the fire of the controlled mind.
A brahmacārī hears only words concerning Kṛṣṇa consciousness. Hearing is the basic principle for understanding, and therefore the pure brahmacārī engages fully in harer nāmānukīrtanam—chanting and hearing the glories of the Lord. He restrains himself from the vibrations of material sounds, and his hearing is engaged in the transcendental sound vibration Hare Kṛṣṇa, Hare Kṛṣṇa. Similarly, the householders, who have some license for sense gratification, perform such acts with great restraint. Sex life, intoxication and meat-eating are general tendencies of human society, but a regulated householder does not indulge in unrestricted sex life and other sense gratification.
Marriage on principles of religious life is therefore current in all civilized human society because that is the way for restricted sex life. This restricted, unattached sex life is also a kind of yajña because the restricted householder sacrifices his general tendency towards sense gratification for higher, transcendental life." Prabhupāda: śrotrādīnīndriyāṇy anye saṁyamāgniṣu juhvati śabdādīn viṣayān anya indriyāgniṣu juhvati [Bg. 4.26] So indriya-saṁyama, yoga. Yoga means indriya-saṁyama. Yoga indriya-saṁyamaḥ.
The yogic practice is recommended for persons who are too much in the bodily concept of life. Anyone... Why anyone? Practically any person.
Therefore this yogic practice was recommended for general population so that they can control the senses. Gradually, one has to take to this platform of indriya-saṁyama, or sattva-guṇa. Rajo-guṇa, sattva-guṇa and tamo-guṇa. So one has to promote himself to the platform of sattva-guṇa. Generally, people are in the rajas-tamo-guṇa.
I was explaining yesterday in the morning, tadā rajas-tamo-bhāvāḥ kāma-lobhādayaś ca ye ceta etair anāviddhaṁ sthita sattve prasīdati [SB 1.2.19] Everyone is trying to be very peaceful and happy. That is possible when one is promoted to the platform of sattva-guṇa. The yoga practice means that. Yoga practice means by controlling the airs within the body...
That will be explained. There are five kinds of air, vāyu. When the airs are not controlled in old age, according to Āyurvedic system, it is called vāyu-roga. The muscles become slackened, old man, because the air control or air circulation is not proper.