The Bhagavad Gita concludes its technical analysis of the body and soul with a powerful statement on perception. In the final verse of Chapter 13, the speaker explains that liberation is only possible for those who can see the "Field" and the "Knower" with a specific spiritual lens.
"Kshetra-kshetrajnayor evam antaram jnana-chakshusha | Bhuta-prakriti-moksham cha ye vidur yanti te param ||"
The Translation:
"Those who, with the Eye of Knowledge (Jnana-Chakshusha), perceive the difference between the Field (the body) and the Knower of the Field (the soul), and understand the process of liberation from the Material Nature (Prakriti), they reach the Supreme."
Physical eyes can only see the "Field" (the physical world and the body). Intellectual eyes can understand the logic of the Gita. But the Jnana-Chakshu is a specific spiritual insight that only comes through a Tattvadarshi Saint (Gita 4.34).
The verse mentions the "liberation from the Material Nature." This refers to:
To reach the Supreme (Param), one must understand how to detach the soul from the influence of the three Gunas. You cannot reach the destination if you do not know you are in a prison. The "Eye of Knowledge" is the map that shows the exit.
The speaker promises that those with this vision reach the Param—the Supreme God.
Meditation can calm the mind, but the "Eye of Knowledge" specifically refers to Right Information (Tatvgyan). You cannot "see" the difference between God and Kaal unless a Tattvadarshi Saint explains the identity of both to you first.
Because Chapter 13 is the most technical chapter. After explaining the "Field," the "Knowers," and the "Supreme Soul," the speaker concludes by saying, "Now that you have the facts, you need the vision to apply them."
Yes. In Gita 15.4 and 15.6, it is confirmed that once a soul reaches that Supreme Abode, it never returns to this world of misery.