The works of Ādi Śaṅkarācārya

Bṛhadāraṇyakopaniṣadbhāṣyam

Verse 324

अथ यस्य जायामार्तवं विन्देत्त्र्यहं

In plain words

If a man's wife begins her monthly courses — for three days... [the source text stops mid-thought here].

Close to the Sanskrit

Now, if a man's wife should come upon her monthly courses — for three days... [the passage breaks off here, continuing in the next fragment].