Mbh 12.336.4d

Guided by this treatise, the Self-born Manu himself will declare to the world its course of duties and observances. When Usanas and Vrihaspati will arise, they also will promulgate their respective treatises on morality and religion, guided by and quoting from this your treatise.[1799] After the publication of this treatise by the Self-born Manu and of that by Usanas, and after the publication of the treatise also by Vrihaspati, this science composed by you will be acquired by king Vasu (otherwise known by the name of Uparichara). Indeed ye foremost of regenerate ones, that king will acquire this knowledge of this work from Vrihaspati. That King, filled with all good thoughts, will become deeply devoted to me. Guided by this treatise, he will accomplish all his religious acts and observances. Verily, this treatise composed by you will be the foremost of all treatise on morality and religion. Possessed of the excellence, this treatise is fraught with instructions for acquiring both Wealth and Religious merit, and is full of mysteries. In consequence of the promulgation of this treatise of yours, ye will be progenitors of an extensive race. King Uparichara also will become endued with greatness and prosperity. Upon the death, however, of that king, this eternal treatise will disappear from the world. I tell you all this.'--Having said these words unto all those Rishis, the invisible Narayana left them and proceeded to some place that was not known to them. Then those sires of the world, those Rishis that bestowed their thoughts on the ends pursued by the world, duly promulgated that treatise which is the eternal origin of all duties and observances. Subsequently, when Vrihaspati was born in Angiras's race in the first or the Krita age, those seven Rishis charged him with the task of promulgating their treatise which was consistent with the Upanishads and the several branches of the Vedas.