Mbh 12.210.3b

As the diverse phenomena of the several seasons appear one after another according to the season that comes, after the like manner creatures start forth into existence at the beginning of every (celestial) yuga. Corresponding with those creatures that start into life is the knowledge of rules and duties that have for their object the regulation of the world's course.[716] At the end of every (celestial) yuga (when universal destruction sets in) the Vedas and all other scriptures disappear (like the rest). In consequence of the grace of the Self-born, the great Rishis, through their penances, first re-acquire the lost Vedas and the scriptures. The Self-born (Brahman) first acquired the Vedas. Their branches called the Angas were first acquired by (the celestial preceptor) Vrihaspati. Bhrigu's son (Sukra) first acquired the science of morality that is so beneficial for the universe. The science of music was acquired by Narada; that of arms by Bharadwaja; the history of the celestial Rishis by Gargya: that of medicine by the dark-complexioned son of Atri. Diverse other Rishis, whose names are connected therewith, promulgated diverse other sciences such as Nyaya, Vaiseshika, Sankhya, Patanjala, etc. Let that Brahma which those Rishis have indicated by arguments drawn from reason, by means of the Vedas, and by inferences drawn from the direct evidence of the senses, be adored. Neither the gods nor the Rishis were (at first) able to apprehend Brahma which is without beginning and which is the highest of the high. Only the divine creator of all things, viz., the puissant Narayana, had knowledge of Brahma. From Narayana, the Rishis, the foremost ones among the deities and the Asuras, and the royal sages of old, derived the knowledge of that highest remedy of the cure of sorrow. When primordial matter produces existences through the action of the primal energy, the universe with all its potencies begins to flow from it.