This is a deep Kabbalistic reference, but I'll try to explain it on its simple level.
The medrash says (the location of the medrash is unknown, but many Rishonim cite the medrash, c.f. Abrabanel Rosh Emana ch. 13) למה נקרא שמו חזיר שעתיד הקב"ה להחזירו לישראל, why is it called a chazir? Because in the future the Holy One will return it (chozer) to Israel.
The Radbaz, 2:828, asks how this medrash fits with the 9th principle of faith, namely that the Torah will not be changed or altered. He explains that this is in actuality a reference to the celestial minister Chaziri"el, who is an accuser of Israel, who in the future will turn around to be a defender of Israel1.
When this accusing celestial minister turns around to defend Israel, the resurrection of the dead will then be possible. Therefore, it is with the return of Chaziri"el that the souls will be returned to their lifeless bodies. We praise Hashem for inspiring Chaziri"el to change his attitude and thereby enable the eventual resurrection.
1 Until here nothing has been made up