Srimad-Bhagavatam: Canto 12 - Chapter 1 - Verse 8
Sanskrit:
न तत्रात्मा स्वयंज्योतिर्यो व्यक्ताव्यक्तयो: पर: ।आकाश इव चाधारो ध्रुवोऽनन्तोपमस्तत: ॥ ८ ॥
ITRANS:
na tatrātmā svayaṁ-jyotiryo vyaktāvyaktayoḥ paraḥākāśa iva cādhārodhruvo ’nantopamas tataḥ
Translation:
The soul within the body is self-luminous and is separate from the visible gross body and invisible subtle body. It remains as the fixed basis of changing bodily existence, just as the ethereal sky is the unchanging background of material transformation. Therefore the soul is endless and without material comparison.