The Self which pervades all things - Shvetashvatara Upanishad

 

The Self which pervades all things, which is the root of self-knowledge and austerity – that is the Truth, the highest mystic doctrine. - Shvetashvatara Upanishad

सर्वव्यापिनमात्मानं क्षीरे सर्पिरिवार्पितम् ।
आत्मविद्यातपोमूलं तद्ब्रह्मोपनिषत् परम् ॥

It pervades, all states, but it is not a state of something else. It is entirely uncaused, independent, complete in itself, beyond time and space, mind and matter.
- Sri Nisargadatta Maharaj