Kaṭha Upaniṣad 30

30

sa tvam agniṃ svargyam adhyeṣi mṛtyo prabrūhi taṃ śraddadhānāya mahyam /
svargalokā amṛtatvaṃ bhajanta etad dvitīyena vṛṇe vareṇa ///1,1.13 //

13. Oh Death! thou knowest the fire which leads to heaven; explain to me who am zealous that (the fire) by which those, whose world is heaven, attain immortality. I pray for this by my second boon.