jyotishaamapi tajjyotistamsaha paramuchyate |
jnyaanam jnyeyam jnyaanagamyam hridi sarvasya vishthitam || 17 ||

That is the light even among all the lights, and it has been spoken of as beyond darkness. It is knowledge, that which is to be known, and the goal of knowledge. It especially resides in the hearts of all.
jyotishaam : among all lights
api : even
tat : that
jyotihi : light
tamsaha : darkness
param : beyond
uchyate : has been spoken
jnyaanam : knowledge
jnyeyam : that which is to be known
jnyaanagamyam : goal of knowledge
hridi : hearts
sarvasya : all
vishthitam : especially resides
In prior verses, the “sat” or existence aspect of the eternal essence was highlighted. Here, the “chit” or awareness aspect is elaborated upon. Awareness or sentience is what makes an entity know about it surroundings as well about itself, as we had seen earlier. Shri Krishna says that the eternal essence is the “light among all the lights”. The word “light” in the Vedas refers to awareness, to knowledge. Which means that ultimately, it is the eternal essence that provides the power of awareness, the power to know, to all beings. Without the eternal essence, we would have no awareness, no sentience.
Imagine a classroom of students that are taking an examination. The student on the last bench can see all of the students in front of him. The student seated in the second to last row can see other students, but not the last row student. Also, the student in the front row cannot see the student in the last row. The awareness provided by the eternal essence is like the student in the last row. The next student is the intellect, followed by the mind and the senses. In other word, the eternal essence gives awareness to the intellect, which gives it to the mind, and then to the senses. But the mind, intellect and senses cannot immediately contact the eternal essence.
Now, just like the word “light” refers to knowledge, the word “darkness” refers to ignorance. By saying that the eternal essence is beyond ignorance, Shri Krishna points out the uniqueness of the awareness aspect of the eternal essence. If we light a lamp in a dark room, it dispels the darkness. We cannot have darkness and light coexist. However, the eternal essence is present in individuals who are ignorance of it, as well as those few rare individuals who have realized it. This unique ability of the eternal essence to illumine ignorance is why Shri Krishna calls it “beyond darkness”.
So, how can we use our antahakarana, our intellect, mind and senses, to realize that eternal essence? Shri Krishna provides a three step process. We use “jnyaanam”, the means of knowledge indicated in the twenty attributes such as humility mentioned earlier in the chapter, to gradually reduce the importance we give to upaadhis or conditionings. As we systematically study the scriptures under the guidance of a teacher, the eternal essence comes into our awareness as “jneyam”, the object of knowledge. But only through constant contemplation, reflection and meditation does the eternal essence becomes “jnyaanagamyam”, the goal of knowledge, where all notions of duality are removed and we remain established in the eternal essence.
Shri Krishna concludes this shloka by reminding us that all these three stages – preparation, study and reflection – are enabled only through the intellect, which is referred to here as the “hridi” or heart of all human beings. Only humans have the capability to access the eternal essence. That is why we come across the statement “a human birth is rare to attain” in many prominent spiritual texts.