The works of Ādi Śaṅkarācārya

Bṛhadāraṇyakopaniṣadbhāṣyam

Verse 361

तस्मादुच्यते नृसिंहमिति ।

In plain words

That is why the mantra says: 'Nṛsiṃha.'

Close to the Sanskrit

Therefore it is said: 'Nṛsiṃham.'