दृष्ट्या पापीयसीं सृष्टिं नात्मानं बह्वमन्यत |
भगवद्ध्यानपूतेन मनसान्यां ततोऽसृजत् ||३
सनकं च सनन्दं च सनातनमथात्मभूः |
सनत्कुमारं च मूनी न्नष्क्रियानूध्वरेतस ||४
Dṛṣṭyā pāpīyasīṁ sṛṣṭiṁ nātmānaṁ bahvamanyat
Bhagavaddhyānapūtena manasānyāṁ tato'sṛjat
Sanakaṁ ca sanandaṁ ca sanātanamathātmabhūḥ
Sanatkumāraṁ ca mūnī nnaṣkriyānūdhvaretasaḥ
When Lord Brahmā decided to commence the sequence of creation, he created five types of ignorance- tama, moha, mahā-moha, tāmisra, and andhatāmisra. Seeing his troublesome creation, he could not appreciate his own doing. Thus, after purifying his mind by meditating upon the lotus feet of the Supreme Lord, Brahmā thought of doing it (the creation) all over again for the second time. Then, Brahmā created the four Kumāras- Sanaka, Sanandan, Sanātana and Sanat-kumāra, who are eternally liberated and are lifelong celibates. The above sequence of events is mentioned in the Srimad Bhāgvat Mahāpuran- Canto 3- Chapter 12- Verses 3 and 4.
The four Kumāras are also known as 'mānas putra' or the sons born out of Brahmā's contemplation. Famous throughout the Puranic literature, they are renowned yogis who requested their father- Brahmā, for the boon of remaining five years old perpetually. They can travel freely to any of the lokas (planes of existence) and are one among the 12 Mahajans- knowers of the divine principle (Bhagavat-dharma).
It is found in Padma Purana that Nārad Muni's quest for absolute knowledge led him to the four Kumāras. Upon this, the four Kumāras declare to Nārad that people must listen to Lord Krishna's pastimes for Bhakti to be established in their hearts. Without Bhakti, no one can obtain true knowledge, nor can they understand the real meaning of true detachment. The only necessary thing to invite Bhakti, Gyān and Vairagya in one's heart is listening to Srimad Bhāgavatam. On hearing this, Nārad Muni requested the four Kumāras to narrate the Srimad Bhāgavatam. The four Kumāras obliged Nārad and thus became the narrator of the Srimad Bhāgvat Mahāpuran.