na srota nanuvaktayam
mukhyo ’py atra mahan asuh
yas tv ihendriyavan atma
sa canyah prana-dehayoh
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
In the body the most important substance is the life air, but that also is neither the listener nor the speaker. Beyond even the life air, the soul also can do nothing, for the Supersoul is actually the director, in cooperation with the individual soul. The Supersoul conducting the activities of the body is different from the body and living force.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The Supreme Personality of Godhead distinctly says in Bhagavad-gita (15.15), sarvasya caham hrdi sannivisto mattah smrtir jñanam apohanam ca: “I am seated in everyone’s heart, and from Me come remembrance, knowledge and forgetfulness.” Although the atma, or soul, is present in every material body (dehino ’smin yatha dehe), he is not actually the chief person acting through the senses, mind and so on. The soul can merely act in cooperation with the Supersoul because it is the Supersoul who gives him directions to act or not to act (mattah smrtir jñanam apohanam ca). One cannot act without His sanction, for the Supersoul is upadrasta and anumanta, the witness and sanctioner. One who studies carefully, under the direction of a bona fide spiritual master, can understand the real knowledge that the Supreme Personality of Godhead is actually the conductor of all the activities of the individual soul, and the controller of their results as well. Although the individual soul possesses the indriyas, or senses, he is not actually the proprietor, for the proprietor is the Supersoul. Consequently the Supersoul is called Hrsikesa, and the individual soul is advised by the direction of the Supersoul to surrender to Him and thus be happy (sarva-dharman parityajya mam ekam saranam vraja). Thus he can become immortal and be transferred to the spiritual kingdom, where he will achieve the highest success of an eternal, blissful life of knowledge. In conclusion, the individual soul is different from the body, senses, living force and the airs within the body, and above him is the Supersoul, who gives the individual soul all facilities. The individual soul who renders everything to the Supersoul lives very happily within the body.