The works of Ādi Śaṅkarācārya

Bṛhadāraṇyakopaniṣadbhāṣyam

Verse 362

अथ कस्मादुच्यते भीषणमिति ।

In plain words

Now the question comes: why does the mantra call him 'the Terrifying One'?

Close to the Sanskrit

Now, why is it said, 'bhīṣaṇam' (the terrifying one)?