The works of Ādi Śaṅkarācārya

Bṛhadāraṇyakopaniṣadbhāṣyam

Verse 346

ससागरं सपर्वतां सप्तद्वीपां वसुं-धरां तत्साम्नः प्रथमं पादं जानीयाद्यक्ष-

In plain words

Know the first foot of that chant as the earth itself — her oceans, her mountains, her seven continents and all... [the sentence is cut short here; this record ends mid-word, before the thought is completed]

Close to the Sanskrit

One should know the first foot of that Sāman [to be] the earth — together with its ocean, its mountains, and its seven continents... [the source text breaks off here, mid-word, at the record boundary]