חזיר means to return, and there is a Midrash that states, להחזירו הוא ברוך הקדוש עתיד לנו, "Hakadosh Baruch Hu will return it to us." Many understand this to mean that there will be a time when a חזיר will be kosher.
This arouses a question because it is known that the Torah won't ever change. How can it be that a chazir will become permitted in the future? The Or HaChaim HaKadosh (11:7) says that the Torah won't change; it is the חזיר that will change. There are two simanim needed for animals to be kosher. They have to chew their cud and have split hooves. Although the chazir has split hooves, it doesn't chew its cud. In the future, it will chew its cud, so it will have two simanim and be kosher. This is implied in the words of the pasuk הוא טמא יגר לא גרה והוא לכם, "If it does not regurgitate its cud, it is tamei for you." The pasuk is stating a condition. It is only not kosher יגור לא גרה, when it doesn't chew its cud. In the future, it will chew its cud, and then it will become kosher..." So, it isn't the Torah that changes, but rather the situation.
The Torah teaches two simanim for animals to be kosher: split hooves and chewing the cud. The Torah (11:4-7) lists four animals with only one siman and are, therefore, not kosher. The animals listed are חזיר ,ארנבת ,שפן ,גמל, camel, hyrax, hare, and chazir.
Rabbeinu b'Chayei writes that these four animals represent the four galuyos: Bavel (the camel/גמל), Yavan (the hyrax/שפן), Madai (hare/ארנבת), and the chazir is galus Edom.
In this week's parashah, there are four pasukim, each pasuk designated to discuss one of these four animals. In parashas Re'eh (Devarim 14:7-8), three animals are mentioned in one pasuk, while chazir, representing Edom, is written alone. This indicates that the galus of Edom will be long and equivalent to all the other three galuyos.
In Tehillim (136), it states four times 'לה הודו to thank Hashem for the salvations that Hashem will give us in these four galuyos. The first three הודוs are written at the beginning of the chapter (...חסדו לעולם כי טוב כי 'לה הודו האדנים לאדני הודו ...חסדו לעולם כי האלקים לאלקי הודו), to thank Hashem for the salvations Hashem will perform for us in the three galus of Bavel (who destroyed the first Beis HaMikdash), Yavan (the miracle of Chanukah) and Madai (the miracle of Purim). The final pasuk of the chapter is חסדו לעולם כי השמים ל"לא הודו. This alludes to the final galus, praising Hashem that He will save us from this galus. It is listed alone, the same as in parashas Re'eh, the chazir is listed alone, to represent the hardships and the length of this bitter galus.
חזיר means return. Why is the animal called חזיר?
Rabbeinu b'Chayei writes three versions of a Midrash that explains why this animal is called חזיר. One is because ברוך הקדוש שעתיד הדין מדת עליהן להחזיר הוא, "Hakadosh Baruch Hu will return onto the [Edomites] Hashem's judgment."
A second version in the Midrash states, לראשה עטרה להחזיר שעתיד, "She will return the crown onto its head." This means that the Edomite nation will build the third Beis HaMikdash. The first two Batei Mikdash were built by Yidden, and Edom, who destroyed the Beis HaMikdash will come and build it.
A third version of the Midrash is: עתיד לנו להחזירו הוא ברוך הקדוש, "Hakadosh Baruch Hu will return it to us."
Rabbeinu b'Chayei writes, "Many understand this to mean that the chazir will one day be kosher for the Jewish nation." Rabbeinu b'Chayei disagrees. "Rather, it is referring to Edom's strength, which used its strength to cause tzaros for Yisrael. In the future, Edom will come with all its strength to support Yisrael..."
