Kabbalah su Genesi 6:14

A proof that even those who emit semen in vain have Teshuva is that the generation of the flood spilled their semen in vain, and our Sages of blessed memory said that Noach slowed the process of building the ark so that he could announce to them to return and do Teshuva. This is what it says in Midrash Tanchuma, Portion of Noach: “Rav Huna said in the name of Rav Yosi: for 120 years the Creator waited for the generation of the flood, since maybe they will do Teshuva, but since they did not do Teshuva he told Noach “make for yourself an arc of gopher-wood” (Genesis 6:14). Noach stood and started planting seeds.”