The works of Ādi Śaṅkarācārya

Muṇḍakopaniṣadbhāṣyam

Verse 14

अतः समुद्रा गिरयश्च सर्वे-ऽस्मात्स्यन्दन्ते सिन्धवः सर्वरूपाः ।

In plain words

From this very source flow all oceans and mountain ranges, and rivers of every conceivable form.

Close to the Sanskrit

Hence all oceans and mountains, and rivers having all forms, flow from this.