तदेतदृचाऽभ्युक्तम् । क्रियावन्तः श्रोत्रिया ब्रह्मनिष्ठाः स्वयं जुह्वत एकर्षिं श्रद्धयन्तः । तेषामेवैतां ब्रह्मविद्यां वदेत शिरोव्रतं विधिवद् यैस्तु चीर्णम्
tadetadṛcā'bhyuktam | kriyāvantaḥ śrotriyā brahmaniṣṭhāḥ svayaṃ juhvata ekarṣiṃ śraddhayantaḥ | teṣāmevaitāṃ brahmavidyāṃ vadeta śirovrataṃ vidhivad yaistu cīrṇam
Sanskrit for this text is pending; the English follows the translator's numbering.
And this is declared by the following Rik-verse: "Let a man tell this science of Brahman to those only who have performed all (necessary) acts, who are versed in the Vedas, and firmly established in (the lower) Brahman, who themselves offer as an oblation the one Rishi (Agni), full of faith, and by whom the rite of (carrying fire on) the head has been performed, according to the rule (of the Âtharvanas)."
Translated by F. Max Müller