“…and you shall enter the ark – you, your sons, your wife, and your sons’ wives with you.”
Rashi comments: “The men separately, and the women separately. From here we learn that they were forbidden to have relations.”
A handful of pesukim later the Torah describes Noach and his family entering the ark.
“Noach, and his sons, and his wife, and his sons’ wives with him, went into the ark because of the waters of the flood.”
Rashi comments: “The men separately, and the women separately, because they were forbidden to have relations, for the world was in a state of distress.”
(A) Why is it necessary for Rashi to repeat himself?
(B) Why does Rashi supply the reason (“for the world was in a state of distress”) only in his second comment, and not initially?