Kaṭha Upaniṣad · 1.3.13
नाचिकेतस्त्वमग्नयं ब्रह्मज्ञमग्निषु त्वमेव । त्वं पारयं सर्वदेवान्यं मृत्युप्रोक्तां सनातनम् ॥ १३॥
nāciketas tvam agnaye brahmajñaagniṣu tvam eva | tvam pārayaṃ sarvadevānyam mṛtyuproktāṃ sanātanam
Naciketas, you are the sacred fire, the knower of Brahman among fires. You transcend all the gods, you are the eternal teaching spoken by Death.
Yama elevates Naciketas to the category of brahma-jña (knower of Brahman) among all sacred fires. This glorification indicates that the sincere seeker, like Naciketas, identifies with truth itself. To “transcend all the gods” means that jñāna (knowledge) goes beyond karma-kāṇḍa (devotional ritualism). Sanātana-dharma is the teaching that endures beyond all temporal form.