R. Samson Raphael Hirsch was no fan of superstitions and gilgul was to him a grave superstition. He was not alone; opponents to this belief include: Rav Saadiah Gaon (Emunos v'Dayos 6:8); Rabbeinu Avraham ben HaRambam (see R. Margoliyos, in his introduction to Milchamos Hashem p. 19 note 11); Rabbi Avraham ibn Daud (Raavad I, in Emunah Ramah 7); Rabbeinu Yitzchak ben Avraham Ibn Latif (Rav Poalim, p. 9 section 21); Rav Chasdai Crescas (Ohr Hashem, ma'amar 4, derash 7); Rav Yosef Albo (Sefer HaIkkarim 4:29); and Rav Avraham Bedersi (Ktav Hitnatzlut leRashba). See too Tosafos Yom Tov (approbation to R' Naftali Hertz Bachrach, Emek HaMelech), who cites Abarbanel that transmigration is an import from Greek philosophy rather than being part of Kabbalah (but contradicted by his comments on yibbum in parshas Ki-teitse), and Rashash to Bava Metzia 107a. (most sources from Rabbi Yitzchak Blau, "Body And Soul: Tehiyyat ha-Metim and Gilgulim in Medieval and Modern Philosophy," The Torah u-Madda Journal vol. 10 (2001)
In his commentary to Genesis 50:2, Rabbi Samson Raphael Hirsch juxtaposes the Jewish belief and the Egyptian belief in immortality. This contrast serves an explicit exegetical purpose in his earlier comments, for it explains Yakov's insistence on being buried in the Land of Canaan rather than being embalmed AND left in Egypt.
" Here we have an interesting contrast between the Egyptian view - as
expressed in embalmment - and the Jewish view. Such contrasts, whenever
they occur, should be analyzed, and should be stressed especially in
our confrontation with those who deny the Divine source of the Torah,
who regard "the work of Moses" as merely the product of "his genius'
which "drew upon the wisdom of the priests of Egypt."
How striking is the contrast that is revealed here! The Egyptian would
embalm the body, so that its individuality should endure. However,
the soul, he thought, did not remain in its personal individuality,
but wandered from body to body - even to animal bodies - in manifold
metamorphoses. The Jew believes that the soul endures forever, whereas
the body wanders. Once the soul has been gathered unto the souls of its
people, the body has nothing more to do with the individual. Rather,
it is a mitzvah to bring the body as soon as possible into close contact
with the decomposing earth (see Sanhedrin 46b). The body returns to dust,
and goes through all the transformations of earthly matter. The Egyptian
believed in the transmigration of the soul, and tried to protect the
body from any possibility of change. The Jew believes in the soul's eternal personal existence, and surrenders the body to earthly change."
The exegetical point would disappear if Egyptians did not believe in transmigration of souls and, in fact, they did not. This misconception, that comes to us through Herodotus but not found in a clear form in the Egyptian sacred texts, may have entered the classical world though the identification of Pythagoros' views on transmigration with the opinions that he brought from his sojourn in Egypt. It was not uncommon for his Greek contemporaries and followers to identify beliefs and rituals of Pythagoreans, strange as many of them appeared in Greek eyes, with Egyptians and Babylonians. The ancient Egyptians embalmed the dead in order that the body might be preserved and accompany the soul into the other world. This rather suggests their belief in resurrection than in reincarnation.