Quran 11:49
The kind of details mentioned in Nuh (AS) case or in case of many other nations and their prophets, are the ones we usually get from akhbar-i-ahaad or in the form of perpetuity of knowledge as traditional parables in a nation. And we have no means to conclusively verify those details. But this attention to details as manifested in words of God is truly an ilm-e-ghaib, because we humans can know about Nuh’s (AS) flood through other means, but these detailed conversations happening between Nuh (AS) and His nation and with His son and with God himself, is truly a great blessing and a piece shared from ilm-e-ghaib by Allah.