פירוש על בראשית 6:13

קץ כל בשר THE END OF ALL FLESH — Wherever you find lewdness and idolatry, punishment of an indiscriminate character comes upon the world killing good and bad alike (Genesis Rabbah 26:5).

VIOLENCE, that is, robbery and oppression. Now G-d gave Noah the explanation [that the flood was due to the fact that the “the earth is filled with] violence” and did not mention “the corruption of the way” [recorded in the preceding verse] because violence is a sin that is known and widely publicized. Our Rabbis have said³⁰Sanhedrin 108a. that it was on account of the sin of violence that their fate was sealed. The reason for it is that the prohibition against violence is a rational commandment,³¹Likewise Ramban above 6:2. See also Yehudah Halevi’s Al Khazari, II, 48, that “the rational laws are the basis and preamble of the divine law, preceding it in character and time, and being indispensable in the administration of every human society.” (Hirschfeld’s translation.) there being no need for a prophet to admonish them against it. Besides, it is evil committed against both heaven and mankind. Thus He informed Noah of the sin for which the end is come — the doom is reached.³²See Ezekiel 7:6-7.

The end of all flesh. That is, the end of their 120 year reprieve.