PURPORT

During one day of Brahma, there are fourteen Manus, and at the end of each Manu, there is devastation up to the earthly planets, and the vast water is fearful even to the personality of Brahma. So in the beginning of the would-be Vaivasvata Manu, such devastation would be seen by him. There would be many other incidences also, such as the killing of the famous Saṅkhasura, etc. This foretelling is by past experience of Brahmaji, who knew that in that fearful devastating scene, the Vedas would come out of his mouth, but the Lord in His fish incarnation not only would save all living entities, namely the demigods, animals, man and the great sages, but would also save the Vedas.