Komentaryo sa Genesis 7:15: Ramban, Radak, Rabbeinu Bahya & Rav Hirsch

AND THEY CAME IN UNTO NOAH INTO THE ARK. The intent of this is to make known that the beasts, fowl, etc., did not gather to him at all, nor did they come until that selfsame day when the rains came. And he came into the ark for it was G-d that hath commanded and His breath which hath gathered them⁸⁴Isaiah 34:16. in one moment.

ויבאו שנים שנים, in pairs, just as the first time. They all showed up, not a single one had disappeared or joined another species.

ויבאו אל נח אל התבה, “they came to Noach, to the Ark.” This verse is a continuation of the words בעצם היום הזה, “on this same day,” in verse 13, where the Torah had mentioned first that Noach and his family entered the Ark before going on to say that the animals arrived in pairs. All this occurred on the same day. The Torah was at pains to describe the miraculous nature of what happened, i.e. that this was a manifestation of G-d’s will.