Muni's PlayKena Upanishad Verse 2.4
Realization occurs when Brahman is recognized as the witness (Sakshi) behind every state of consciousness. By identifying with this eternal witness rather than the passing states of mind, the seeker gains spiritual strength and enters into the state of immortality.
Sanskrit Verse
प्रतिबोधविदितं मतममृतत्वं हि विन्दते ।
आत्मना विन्दते वीर्यं विद्यया विन्दतेऽमृतम् ॥ १२ ॥
Transliteration
pratibodhaviditaṃ matamamṛtatvaṃ hi vindate |
ātmanā vindate vīryaṃ vidyayā vindate’mṛtam || 12 ||
Translation
(The Brahman) is known well, when it is known as the witness of every state of consciousness; for (by such knowledge) one attains immortality. By his Self he attains strength and by knowledge, immortality.