Those who know this, they become immortal. Those who know this, they become immortal.

Emphatic repetition of the promise of immortality. The “this” (etad) refers to the ākāśa antarhṛdaya, the inner space of the heart where the universe is established. In our yoga practice, this is not a promise of eternal bodily life but recognition that we were never born nor will we die. Knowing the space of the heart is knowing the dimension that transcends time. The double affirmation is a guarantee: whoever knows, is. Immortality is not a future state but the always-present nature of whoever knows Reality.