The Bhagavad Gita with Commentaries of Ramanuja, Madhva, Shankara and Others.
Bhagavad Gita 14.19
http://www.bhagavad-gita.us/articles/148/1/Bhagavad-Gita-1419/Page1.html
By Bhagavan Sri Krishna
 

Text 19

nanyam gunebhyah kartaram
yada drastanupasyati
gunebhyas ca param vetti
mad-bhavam so ’dhigacchati

Translation

When one properly sees that in all activities no other performer is at work than these modes of nature and he knows the Supreme Lord, who is transcendental to all these modes, he attains My spiritual nature.

Commentary by Srila Prabhupada

One can transcend all the activities of the modes of material nature simply by understanding them properly by learning from the proper souls. The real spiritual master is Krishna, and He is imparting this spiritual knowledge to Arjuna. Similarly, it is from those who are fully in Krishna consciousness that one has to learn this science of activities in terms of the modes of nature. Otherwise, one’s life will be misdirected. By the instruction of a bona fide spiritual master, a living entity can know of his spiritual position, his material body, his senses, how he is entrapped, and how he is under the spell of the material modes of nature. He is helpless, being in the grip of these modes, but when he can see his real position, then he can attain to the transcendental platform, having the scope for spiritual life. Actually, the living entity is not the performer of different activities. He is forced to act because he is situated in a particular type of body, conducted by some particular mode of material nature. Unless one has the help of spiritual authority, he cannot understand in what position he is actually situated. With the association of a bona fide spiritual master, he can see his real position, and by such an understanding he can become fixed in full Krishna consciousness. A man in Krishna consciousness is not controlled by the spell of the material modes of nature. It has already been stated in the Seventh Chapter that one who has surrendered to Krishna is relieved from the activities of material nature. For one who is able to see things as they are, the influence of material nature gradually ceases.

Commentary by Sri Visvanatha Cakravarti Thakur

Having shown the repeated births caused by association with the gunas, the Lord now shows liberation, which is beyond the gunas in two verses. When the jiva (drasta) does not observe any other doer than the gunas, which change into the form of agent, the action and the object; when he realizes that only the gunas are always the doers, and knows the soul is separate from the gunas; the jiva attains (adhigacchati) merging with me (mad bhavam). It should be understood from the second to last verse in this chapter that one must still perform bhakti even after practicing such jnana, in order to get this result.