The works of Ādi Śaṅkarācārya

Chāndogyopaniṣadbhāṣyam

Verse 293

यद्वविज्ञातमिवाभूदित्येतासामेव देव-तानां समास इति तद्विदांचक्रुर्यथा तुखलु सोम्येमास्तिस्रो देवताः पुरुषं प्राप्यत्रिवृत्त्रिवृदेकैका भवति तन्मे विजानी-हीति ॥ ७ ॥

In plain words

That which appeared as if unrecognized is the combination of these very deities—thus the knowers understood. But how these three deities, my dear, having entered the human being, each become triple—learn that from me.

Close to the Sanskrit

That which appeared unrecognized, that is the combination of these very deities, thus the knowers understood; but how indeed, dear one, these three deities, having reached the person, each and every one becomes triple, that learn from me, thus.