The works of Ādi Śaṅkarācārya

Bṛhadāraṇyakopaniṣadbhāṣyam

Verse 328

अथ य इच्छेत्पुत्रो मे श्यामो लोहिताक्षो जायेत त्रीन्वेदानुब्रुवीत सर्वमायुरियादित्युदौदनं पाचयित्वा सर्पिष्मन्तमश्नीयातामीश्वरौ जनयितवै ॥ १६ ॥

In plain words

Now, if a man wishes for a dark, red-eyed son who masters all three Vedas and lives his full life, the two of them should eat rice cooked in plain water, together with ghee — and so they become able to bring such a son into being.

Close to the Sanskrit

Now, if he should desire: 'may a dark, red-eyed son be born to me; may he master the three Vedas; may he attain his full lifespan' — then, having had rice cooked in water alone, the two should eat it with ghee; [thereby] they become capable of begetting [such a son].