Srimad Bhagvata Mahapurana: Book 6: Chapter 10: Verses 1-15
Sri Suka began again : Having thus fully instructed Indra, Lord Sri Hari, the Protector of the universe, disappeared on that very spot, while the gods (who are noted for their unwinking eyes) kept looking on. Solicited by the gods in the aforesaid manner (as instructed by the Lord), and (greatly) rejoicing, the magnanimous sage Dadhici (the son of Atharva) replied as follows, as though jesting, O Pariksit (a scion of Bharata) :- "O gods, have you no idea of the pain that is actually caused to embodied beings at the time of death-a pain so hard to bear that it robs them (even) of their consciousness ? The body is the dearest object in this life, (particularly) sought after by living beings that are eager to survive. Who would have the courage to part with it even for Lord Visnu, should He ask for it ?" The gods replied : Now what is that which is difficult to part with, O (holy) Brahmana, for magnanimous souls like you, who are compassionate to (all) living beings and whose (noble) deeds are extolled (even) by men of sacred renown? Surely selfish people do not realize the difficulty of the donor; if they know it, they would not ask a gift (of him). And a donor (too) would not say "No", when capable of granhing their request.
The sage (Dadhici) said : I replied to you (as I have done) only because I wished to hear from you about Dharma (righteousness), Here do I so on, that exist for others). The everlasting virtue practised by men of sacred renown consists merely in this that a man himself grieves and rejoices in sympathy with the grief and joy of his fellow-beings. Oh, what a pity, Oh, how painful it is that a mortal should not serye others with his wealth, sons and other kinsmen and body, which besides being transitory (by nature), are not only of no use to him but (really) belong to others. Sri Suka continued : Having thus made up his mind and merging his (individual) self in the Lord, the Supreme Reality, the sage Dadhici, the son of Atharva, dropped his body. Having controlled his senses, vital airs, mind and intellect, his eyes fixed on the (absolute) Truth and (all) fetters (in the form of virtue and sin) broken, he established himself in supreme Yoga (perfect identity with Brahma), so that he did not know when the body (actually) fell. Now, taking up the thunderbolt, forged by Viswakarma (the heavenly artisan) out of the bones of the sage Dadhici, and endowed with the Lord's energy, Indra felt very strong. Surrounded by all the hosts of gods, he was being extolled by crowds of sages and shone on (the back of) Airavata (the king of the elephants), as though delighting (all) the three worlds (heaven, earth and the intermediate region). In order to cut down Vrtra, who was surrounded by generals of demon cohorts, he assailed the demon with (great) impetuosity and full of wrath, O Pariksit, even as Rudra (the god presiding over destruction) rushes against Death (at the time of universal destruction).