yavan manas tyajet kaman
yato yato nihsarati
manah kama-hatam bhramat
tatas tata upahrtya
hrdi rundhyac chanair budhah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
While continuously staring at the tip of the nose, a learned yogi practices the breathing exercises through the technical means known as puraka, kumbhaka and recaka — controlling inhalation and exhalation and then stopping them both. In this way the yogi restricts his mind from material attachments and gives up all mental desires. As soon as the mind, being defeated by lusty desires, drifts toward feelings of sense gratification, the yogi should immediately bring it back and arrest it within the core of his heart.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The practice of yoga is concisely explained herein. When this practice of yoga is perfect, one sees the Supersoul, the Paramatma feature of the Supreme Personality of Godhead, within the core of one’s heart. However, in Bhagavad-gita (6.47) the Supreme Lord says:
yoginam api sarvesam
sraddhavan bhajate yo mam
sa me yuktatamo matah
“Of all yogis, he who always abides in Me with great faith, worshiping Me in transcendental loving service, is most intimately united with Me in yoga and is the highest of all.” A devotee can immediately become a perfect yogi because he practices keeping Krsna constantly within the core of his heart. This is another way to practice yoga easily. The Lord says:
man-mana bhava mad-bhakto
mad-yaji mam namaskuru
“Always think of Me and become My devotee. Worship Me and offer your homage unto Me.” (Bg. 18.65) If one practices devotional service by always keeping Krsna within the core of his heart (man-manah), he immediately becomes a first-class yogi. Furthermore, keeping Krsna within the mind is not a difficult task for the devotee. For an ordinary man in the bodily concept of life, the practice of yoga may be helpful, but one who immediately takes to devotional service can immediately become a perfect yogi without difficulty.