The works of Ādi Śaṅkarācārya

Viṣṇusahasranāmastotram

Verse 67

अग्निर्यथैको भुवनं प्रविष्टोरूपं रूपं प्रतिरूपो बभूव ।एकस्तथा सर्वभूतान्तरात्मारूपं रूपं प्रतिरूपो बहिश्च ॥

In plain words

Just as fire enters the world as one yet takes the exact shape of every object it burns, so the one inner self of all beings dwells within every distinct form while also transcending them all.

Close to the Sanskrit

As fire, being one, having entered the world, became corresponding in form to every single form, so the inner self of all beings is one, and is corresponding in form to every single form, and is outside too.