TT #7 · Parashas Noach · First Aliyah · Passuk 6:13
God said to Noach: “The end of all flesh has come before Me, for the earth is filled with violence through them; and behold, I am about to destroy them with the earth.”
Torah Temimah points to Sanhedrin 108a (R’ Yochanan on the power of chamas).
E-Daf image — Sanhedrin 108a (size=3)
Shas / HebrewBooks PDF of the daf
English: “For the earth is filled with violence” — R’ Yochanan said: Come and see how great is the power of violence (chamas/robbery), for the generation of the Flood transgressed everything, yet the decree was not sealed against them until they stretched out their hands in robbery.
Custom (identification of the decisive sin from the verse’s explicit focus on chamas).
Robbery/violence was the sin that sealed the fate of the generation of the Flood, even more than the other transgressions they committed.