וַֽיְהִ֧י הַמַּבּ֛וּל אַרְבָּעִ֥ים י֖וֹם עַל־הָאָ֑רֶץ וַיִּרְבּ֣וּ הַמַּ֗יִם וַיִּשְׂאוּ֙ אֶת־הַתֵּבָ֔ה וַתָּ֖רָם מֵעַ֥ל הָאָֽרֶץ׃
И потоп был на земле сорок дней; и воды увеличились, и понесли ковчег, и он был поднят над землей.
Rashi
ויהי הגשם על הארץ AND THE RAIN WAS UPON THE EARTH — But later on (v. 17) it says. “And the Flood was upon the earth”! But the explanation is this: when He poured down the water at first He made it fall in mercy (gently), in order that if the people would repent, it might prove a rain of blessing; but when they did not repent it became a destructive flood (Genesis Rabbah 31:12) .