By the measure drawn from one's own self, the self itself being the standard by which a thing is measured, he who sees everywhere, in all beings, what is the same and equal, that one, Arjuna. And what does he see as the same? Just as happiness is wished-for by me, so is happiness welcome to every living being; and just as pain is unwelcome and unwished-for by me, so is pain unwelcome and contrary to every living being. Measuring thus by his own self, he sees happiness and pain, the welcome and the contrary, as the same in all beings, and acts contrary to none: he does no harm. He who is in this way harmless, established in right vision, that yogin is held to be the highest, the foremost among all yogins. Seeing that this yoga, marked by right vision as described, is hard to win, and wishing surely to learn the means of attaining it, Arjuna said.

He who, by the likeness, through their having unconstricted knowledge for their single form, of his own self and of the other selves, sees as the same, by the likeness of their non-connection with him, the happiness in the form of the birth of a son and the rest, and the pain in the form of his death and the rest, that go about in his own self and in all others everywhere; he who sees the birth, death, and the rest of another's son as the same as the birth, death, and the rest of his own son; that yogin, gone to the supreme summit of the discipline, is held to be.

This is a brief sub-gloss. For a fuller reading of this verse, see Madhusūdana, Śaṅkara, or Rāmānuja above.

Krishna explains the sameness in another way, with 'by the likeness to oneself'.