BṚHADĀRAṆYAKA UPANISHAD · 3.7.5

यो ऽग्नौ तिष्ठन्न् अग्नेर् अन्तरो यम् अग्निर् न वेद यस्याग्निः शरीरं यो ऽग्निम् अन्तरो यमयत्य् एष त आत्मान्तर्याम्य् अमृतः ॥

yo ’gnau tiṣṭhann agner antaro yam agnir na veda yasyāgniḥ śarīraṃ yo ’gnim antaro yamayaty eṣa ta ātmāntaryāmy amṛtaḥ ॥

'He who dwells in the fire, and within the fire, whom the fire does not know, whose body the fire is, and who pulls (rules) the fire within, he is thy Self, the puller (ruler) within, the immortal.'

F. Max Müller · The Upanishads, Sacred Books of the East 15 (1884)