mamaham iti dehadau
dhasye mano bhagavati
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Simply because I chanted the holy name of the Lord in the association of devotees, my heart is now becoming purified. Therefore I shall not fall victim again to the false lures of material sense gratification. Now that I have become fixed in the Absolute Truth, henceforward I shall not identify myself with the body. I shall give up false conceptions of “I” and “mine” and fix my mind on the lotus feet of Krsna.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
How a living entity becomes a victim of the material condition is lucidly explained in this verse. The beginning is to misidentify the body as one’s self. Therefore Bhagavad-gita begins with the spiritual instruction that one is not the body, but is within the body. This consciousness can be possible only if one chants the holy name of Krsna, the Hare Krsna maha-mantra, and always keeps oneself in the association of devotees. This is the secret of success. Therefore we stress that one should chant the holy name of the Lord and keep oneself free from the contaminations of this material world, especially the contaminations of lusty desires for illicit sex, meat-eating, intoxication and gambling. With determination, one should vow to follow these principles and thus be saved from the miserable condition of material existence. The first necessity is to become freed from the bodily concept of life.