Srimad-Bhagavatam: Canto 12 - Chapter 1 - Verse 2-5

Sanskrit:

आहुश्चिरायुषमृषिं मृकण्डतनयं जना: ।य: कल्पान्ते ह्युर्वरितो येन ग्रस्तमिदं जगत् ॥ २ ॥स वा अस्मत्कुलोत्पन्न: कल्पेऽस्मिन् भार्गवर्षभ: ।नैवाधुनापि भूतानां सम्प्लव: कोऽपि जायते ॥ ३ ॥एक एवार्णवे भ्राम्यन् ददर्श पुरुषं किल ।वटपत्रपुटे तोकं शयानं त्वेकमद्भ‍ुतम् ॥ ४ ॥एष न: संशयो भूयान् सूत कौतूहलं यत: ।तं नश्छिन्धि महायोगिन् पुराणेष्वपि सम्मत: ॥ ५ ॥

ITRANS:

āhuś cirāyuṣam ṛṣiṁmṛkaṇḍu-tanayaṁ janāḥyaḥ kalpānte hy urvaritoyena grastam idaṁ jagat

Translation:

Authorities say that Mārkaṇḍeya Ṛṣi, the son of Mṛkaṇḍu, was an exceptionally long-lived sage who was the only survivor at the end of Brahmā’s day, when the entire universe was merged in the flood of annihilation. But this same Mārkaṇḍeya Ṛṣi, the foremost descendant of Bhṛgu, took birth in my own family during the current day of Brahmā, and we have not yet seen any total annihilation in this day of Brahmā. Also, it is well known that Mārkaṇḍeya, while wandering helplessly in the great ocean of annihilation, saw in those fearful waters a wonderful personality — an infant boy lying alone within the fold of a banyan leaf. O Sūta, I am most bewildered and curious about this great sage, Mārkaṇḍeya Ṛṣi. O great yogī, you are universally accepted as the authority on all the Purāṇas. Therefore kindly dispel my confusion.

Purport:

Lord Brahmā’s day, consisting of his 12 hours, lasts 4 billion 320 million years, and his night is of the same duration. Apparently Mārkaṇḍeya lived throughout one such day and night and in the following day of Brahmā continued living as the same Mārkaṇḍeya. It seems that when annihilation occurred during Brahmā’s night, the sage wandered throughout the fearful waters of destruction and saw within those waters an extraordinary personality lying on a banyan leaf. All of these mysteries concerning Mārkaṇḍeya will be clarified by Sūta Gosvāmī at the request of the great sages.