1)
What is HaSh-m telling Noach here, that He has not already told him?
1.
Rashi: HaSh-m is now showing him the rainbow which, until now, He was telling him about.
2.
Seforno: He is showing him the second rainbow and telling him that, when he, and Tzadikim like him, see it, they must play their part by (Davening and) arousing the people to do Teshuvah.
