Kaṭha Upaniṣad 31

31

evaṅ guṇaviśiṣṭasya svargalokasya prāptisādhanabhūtaṃ svargyam agniṃ sa tvaṃ mṛtyur adhyeṣi smarasi jānāsīty arthaḥ / he mṛtyo yatas taṃ prabrūhi kathaya śraddadhānāya śraddhāvate mahyaṃ svargārthine / yenāgninā citena svargalokaḥ svargo loko yeṣāṃ te svargalokā yajamānā amṛtatvam amaraṇatāṃ devatvaṃ bhajante prāpnuvanti tad etad agnivijñānaṃ dvitīyena vareṇa vṛṇe ///1,1.13 //

Shankara’s Commentary:
Com.—The fire, which helps one to attain the heaven possessed of such attributes, thou, Oh Death! knowest; and as thou knowest, teach me who am zealous by which fire sacrificing, men attain heaven and immortality or become Devas. This knowledge of the fire, I crave by my second boon.