Lineage of Prajapati - Verse 119-120

In. every Treta Age Svayaxiibhuva (Manu) , the eldest son of Brahma, the Supreme God, is the only knower of all lores which he classifies in the Dvapara Age. In the Vaivasvata Manvantara, it is Brahma who teaches that lore at the outset.