Lord Krishna told Arjuna that the mind is the root cause of everything and must be controlled. Arjuna doubted whether it was possible to bring the mind under control because of its fickleness. It will churn and stir the faculties, cannot be controlled by introspection, and is involved and immersed in worldly things. It is as difficult as restraining a strong wind with such things as a fragile fan.
Valayapettai Sri Ramachariar said in a discourse that Lord Krishna replied through two verses (Chapter VI slokas 35 and 36) that the mind could be controlled by constant practice of yoga and by detachment and desires (Abhyasam and Vairagyam).
Arjuna raised the question of what would happen to a person who discontinued yoga after starting the practice. What way does he go? Does he not perish like a small piece of cloud riven from a large mass of cloud without reaching another mass? Has he not lost his way, who has just begun to traverse the path leading to Brahman?
Sri Krishna replied to Arjuna that any good deed undertaken by a person will not fail to yield benefits. He who has drifted away from yoga practice will, after enjoying the benefits of swarga loka, be born into a family of pure who practice yoga. The yogi becomes cleansed through the accumulation of merits collected in various births, and he reaches the supreme state, though he had gone astray before.
