Mahabharata 12.337.41

12.337.41

śrībhagavānuvāca |
manvantareṣu putra tvamevaṃ lokapravartakaḥ |
bhaviṣyasyacalo brahmannapradhṛṣyaśca nityaśaḥ || 41 ||

From this syllable of speech (Saraswati) arose a Rishi of the name Saraswat. The son, thus born of the Speech of Narayana, came to be, also called by the name of Apantara-tamas. Endued with great puissance, he was fully conversant with the past, the present, and the future. Firm in the observance of vows, he was truthful in speech. Unto that Rishi who, after birth, had bowed his head unto Narayana, the latter, who was the original Creator of all the deities and possessed of a nature that was immutable, said those words: Thou shouldst devote thy attention to the distribution of the Vedas, O foremost of all persons endued with intelligence. Do thou, therefore, O ascetic, accomplish what I command thee.--In obedience to this command of the Supreme Lord from whose Speech the Rishi Apantaratamas sprang into existence, the latter, in the Kalpa named after the Self-born Manu, distributed and arranged the Vedas. For that act of the Rishi, the illustrious Hari became gratified with him, as also for his well-performed penances, his vow and observances, and his restraint of the senses or passions. Addressing him,--Narayana said,--At each Manwantara, O son, thou wilt act in this way with respect to the Vedas. Thou shalt, in consequence of this act of thine, be immutable, O regenerate one, and incapable of being transcended by any one. When the Kali age will set in, certain princes of Bharata's line, to be called by the name of Kauravas, will take their birth from thee.