Śrīmad-Bhāgavatam · Text 1.3.9
Who is speaking and story frame
तुर्ये धर्मकलासर्गे नरनारायणावृषी ।
भूत्वात्मोपशमोपेतमकरोद्दुश्चरं तप: ॥ ९ ॥
turye dharma-kalā-sarge
nara-nārāyaṇāv ṛṣī
bhūtvātmopaśamopetam
akarot duścaraṁ tapaḥ
In the fourth incarnation, the Lord became Nara and Nārāyaṇa, the twin sons of the wife of King Dharma. Thus He undertook severe and exemplary penances to control the senses.
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