English: “On that very day” — Why “on that very day”? Because the people of his generation were saying: “We will not let him enter the ark; we will take axes and hatchets and split the ark.” The Holy One, blessed be He, said: “I will bring him into the ark in the very essence of the day, and whoever has the power to protest, let him come and protest.”
On the daf / in context: The emphatic phrase “be-etzem ha-yom” underscores that the entry took place in broad daylight, publicly, so that no one could claim the generation was prevented from intervening.
Type of Learning
Custom (diyuk from the emphatic “be-etzem ha-yom”).
What Is Learned
Noach entered the ark in full public view so that the generation could not claim they were denied the chance to stop him.