The works of Ādi Śaṅkarācārya

Chāndogyopaniṣadbhāṣyam

Verse 118

तद्व्यक्षरत्तदादित्यमभितोऽश्रयत्तद्वा एतद्यदेतदादित्यस्य रोहितं रूपम् ॥ ४ ॥

In plain words

That essence flowed forth and sheltered around the sun. Indeed, this is what appears as the red form of the sun.

Close to the Sanskrit

That flowed forth; that approached the sun all around and sheltered. That indeed is this which is the red form of the sun.