Verse 2.15-16

Verse 2.15: “He, the manly one, whom these, O Best of men perturb not: he the steadfast one, even-poised betwixt pain and pleasure, he can properly claim deathlessness.

Verse 2.16: For the non-existent there is no coming into existence, nor passing out of existence for the existent. The true nature of these twain has alike been seen by the Seers of Truth. (123)

Commentary called Jnaneshwari by Jnaneshwar:

One that does not get entangled in the sense-objects is affected neither by happiness nor by sorrow and he is ever free from the evil of being born a mother’s son. He does not get involved in the sense objects for the pleasure of the senses and is alone, know ye, eternal. Now Arjuna, hear another thing I tell you. Those who are thoughtful only know it. There is in this world one all-pervading and hidden spiritual essence which only the learned always accept as real. Just as milk mixed with water appears one but can be separated by the swan alone, or just as the intelligent can separate pure gold from the alloy by burning the latter in a furnace, or just as butter can be extracted by skilfully churning the curds, or just as from mixed up seed and chaff, when winowed, the chaff is blown away leaving behind only the seed—even so the wise and the learned truth-seers easily get free from the shackles of empirical existence seeing it to be unreal after deep thinking and then their gaze is fixed on the real alone. Therefore the wise seers have no attachment for things which are not eternal since they have realized that only the eternal Atman is real while the non-eternal and changing world of sense is unreal.