Yoga Sutras of Patanjali translated by Yogi Kalinath - Chapter 4, Verse 26
Pada 4, Sutra 26
Tadaa viveka– nimnam kaivalya-praag-bhaaram cittam
Then consciousness, inclined towards discernment, moves toward Liberation.
An interiorized consciousness that is absorbed in the awareness of the Self, the Eternal Witness, becomes irreversibly in a state of discernment between the ephemeral (the seen) and the perennial (Atman / Purusha). Pure subjectivity is attained and the Seer is no longer identified as either the owner or doer. This is what is meant by the state of Liberation.
True alone-ness or subjectivity leads to all-one-ness. There is no self but the Self and that Self is the Self of all selves.