na kutascit parabhavah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
There is no defeat in this material world for persons who control the mind and senses by controlling the breathing process and who are therefore experienced, mature mystics. This is because by such perfection in yoga they have attained your mercy.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The purpose of yogic performances is explained here. It is said that an experienced mystic attains full control of the senses and the mind by controlling the breathing process. Therefore, controlling the breathing process is not the ultimate aim of yoga. The real purpose of yogic performances is to control the mind and the senses. Anyone who has such control is to be understood to be an experienced, mature mystic yogi. It is indicated herein that a yogi who has control over the mind and senses has the actual benediction of the Lord, and he has no fear. In other words, one cannot attain the mercy and benediction of the Supreme Lord until one is able to control the mind and the senses. This is actually possible when one fully engages in Krsna consciousness. A person whose senses and mind are always engaged in the transcendental service of the Lord has no possibility of engaging in material activities. The devotees of the Lord are not defeated anywhere in the universe. It is stated, narayana-parah sarve: one who is narayana-para, or a devotee of the Supreme Personality of Godhead, is not afraid anywhere, whether he is sent to hell or promoted to heaven (Bhag. 6.17.28).