Comentário sobre Números 16:31

ככלתו לדבר את כל הדברים, "when he finished saying all this," The earth timed its action at the precise moment when Moses completed what he had to say. As soon as Moses was finished it swallowed Korach, etc.

ותבקע האדמה אשר תחתיהם, ותפתח הארץ את פיה ותבלע אותם, “The ground which was beneath them split open and the earth opened its ‘mouth’ and swallowed them.” Nachmanides explains why the Torah had to mention both אדמה and ארץ as “opening” in this verse. Had the Torah only written that the ground split open, the phenomenon could have been considered as an ordinary earthquake, although Moses had predicted the time and the place. This is why the Torah added the words “the earth opened its mouth” to tell us that a great miracle, unparalleled, happened here. This is why the miracle had been predicted as a בריאה, a new creation. The place where this took place returned to its original appearance as distinct from an earthquake which leaves behind clear evidence that there had been an upheaval.

ואת כל האדם אשר לקרח, “and every human being belonging to Korach.” This refers to the members of his household and all the rebels accepting his leadership. Korach’s sons were also “swallowed” by the earth but they did not die as a result; this is the meaning of Numbers 26,11: “and the sons of Korach did not die.” Our sages (Megillah 14) explain that a “fortified” place was reserved for them in purgatory where they stayed. [I suppose the meaning is a site safe from the fires of purgatory but inside it. Ed.]
It is possible to explain the verse differently by understanding the words ואת כל האנשים, “and all the men,” as including only the people previously described in verse 30 as כי נאצו האנשים האלה את ה', “for these men had provoked Hashem.” The reason that the Torah called the people who were swallowed as אדם is because they were swallowed by the אדמה, i.e. they returned to the place they originally came from [as in “dust thou art and to dust thou shall return.” Ed.]