The Prashna Upanishad with Shankara’s Commentary
अरा इव रथनाभौ कला यस्मिन् प्रतिष्टिताः । तं वेध्यं पुरुषं वेद यथ मा वो मृत्युः परिव्यथा इति ॥ ६ ॥
arā iva rathanābhau kalā yasmin pratiṣṭitāḥ | taṃ vedhyaṃ puruṣaṃ veda yatha mā vo mṛtyuḥ parivyathā iti || 6 ||
6. Know that knowable Purusha in whom the kalâs are centred like spokes in the nave of a wheel. So, death, may not harm you.
Com.—As the spokes of a wheel are centred in the nave of the wheel, and depend on it, so the kalâs, Prâna, etc., are centred in the Purusha during their creation, support and destruction. Know that Purusha the Âtman of all kalâs, worthy to be known (Purusha, because he is all-pervading, or because he stays in the heart); so, O disciples! death may not harm you. If the Purusha be not known, you will certainly become miserable, subject to the grief caused by death. The drift is that it may not so befall them.