KeU 2.4
प्रतिबोधविदितं मतममृतत्वं हि विन्दते । आत्मना विन्दते वीर्यं विद्यया विन्दतेऽमृतम्
It (Brahman) is known, when It is known in every state of consciousness. (Through such knowledge) one attains immortality. By attaining this Self, man gains strength; and by Self-knowledge immortality is attained.
Translated by Swami Paramananda
'It is thought to be known (as if) by awakening, and (then) we obtain immortality indeed. By the Self we obtain strength, by knowledge we obtain immortality.
Translated by F. Max Müller