This can be stated in active form. AT: "the people of this generation must reject him" (See: [[rc://en/ta/man/translate/figs-activepassive]])
# As it happened in the days of Noah
The "days of Noah" refers to the time during Noah's life just before God punished the people of the world. AT: "As people were doing in the days of Noah" or "As people were doing when Noah lived"
# even so will it also happen in the days of the Son of Man
The "days of the Son of Man" refers to the period just before the Son of Man will come. AT: "people will be doing the same things in the days of the Son of Man" or "people will be doing the same things when the Son of Man is about to come"
# They ate, they drank, they married, and they were given in marriage