The works of Ādi Śaṅkarācārya

Bṛhadāraṇyakopaniṣadbhāṣyam

Bhashya

Bhashya

प्रतीकं मुखेनेत्येतत् ।स देवानपिगच्छति स ऊर्जमुपजीवतीति प्रशंसा ॥ २ ॥

In plain words

This refers to approaching through the mouth as a symbol. He attains the deities and subsists on supreme spiritual vigor—this is the concluding praise.

Close to the Sanskrit

Symbolically through the mouth, this is it. He reaches the gods, he lives upon divine vigor—this is the praise.