One verse

Srimad Bhagavatam 10.47.31

10.47.31

आत्मा ज्ञानमय: शुद्धो व्यतिरिक्तोऽगुणान्वय: । सुषुप्तिस्वप्नजाग्रद्भ‍िर्मायावृत्तिभिरीयते ॥ ३१ ॥

ātmā jñāna-mayaḥ śuddho vyatirikto ’guṇānvayaḥ suṣupti-svapna-jāgradbhir māyā-vṛttibhir īyate

ātmā
the soul
jñāna-mayaḥ
comprising transcendental knowledge
śuddhaḥ
pure
vyatiriktaḥ
separate
aguṇa-anvayaḥ
uninvolved in the reactions of the material modes
suṣupti
in deep sleep
svapna
ordinary sleep
jāgradbhiḥ
and waking consciousness
māyā
of the material energy
vṛttibhiḥ
by the functions
īyate
is perceived

Being composed of pure consciousness, or knowledge, the soul is distinct from everything material and is uninvolved in the entanglements of the modes of nature. We can perceive the soul through the three functions of material nature known as wakefulness, sleep and deep sleep.