וַיָּשֻׁ֧בוּ הַמַּ֛יִם מֵעַ֥ל הָאָ֖רֶץ הָל֣וֹךְ וָשׁ֑וֹב וַיַּחְסְר֣וּ הַמַּ֔יִם מִקְצֵ֕ה חֲמִשִּׁ֥ים וּמְאַ֖ת יֽוֹם׃
And the waters returned from off the earth continually; and after the end of a hundred and fifty days the waters decreased.
Read kabbalistic (mystical) interpretation of Genesis 8:3: and classical mystical sources.