Among the lesser-known of the Torah’s 613 commands is that of "Pidyon Peter Hamor," the obligation to redeem a firstborn donkey, which the Torah presents in Parashat Bo. As the Rambam (Rabbi Moshe Maimonides, Spain-Egypt, 1135-1204) explains (listen to audio recording for precise citation), one redeems the firstborn donkey by giving a live sheep to a Kohen. If one does not want to give a sheep, then he must break the donkey’s neck and kill it. It is preferable to give a sheep to a Kohen instead of killing the donkey. The sheep given to the Kohen is one of the 24 Matanot ("gifts") which a Kohen receives from the rest of the Jewish Nation. A firstborn donkey is forbidden for any kind of use before it is redeemed, and if it is sold before its redemption, then the money received in exchange for the donkey is forbidden for use. The obligation to redeem the donkey takes effect immediately after its birth. After thirty days, one has the option to either give a sheep or sell it.

If one gives the donkey itself to a Kohen, the Kohen may not use it until it is redeemed. Kohanim and Leviyim are not included in this Misva, and are not required to redeem their firstborn donkey. If one owns a firstborn donkey in partnership with a non-Jew, it does not have to be redeemed. The sheep given to the Kohen has no special status of sanctity, and the Kohen may do with it whatever he pleases.

The Misva of Peter Hamor applies in all places and at all times; it is not confined to Eretz Yisrael or to the times when the Bet Ha’mikdash stands.

The Sefer Ha’hinuch (anonymous Medieval work discussing the 613 Biblical commands), in Misva 22, writes that the underlying reason of this Misva is to commemorate the miracle of the Exodus from Egypt, when G-d miraculously killed the firstborns of Egypt but not those of Beneh Yisrael. Rashi (Rabbi Shlomo Yishaki of Troyes, France, 1040-1105), in his Torah commentary, gives two other reasons, after noting that the donkey is the only non-kosher animal that is accorded a special status such that a firstborn requires redemption. He first explains that the ancient Egyptians were compared to donkeys (as the Pasuk says, "U’bsar Hamorim Besaram"), while Beneh Yisrael are compared to sheep ("Seh Pezura Yisrael"), and the redemption thus symbolizes Hashem’s choosing Beneh Yisrael over the Egyptians. Secondly, the Midrash relates that when Beneh Yisrael left Egypt, each and every person had several donkeys laden with spoils which they took with them. We express our gratitude to the donkeys for helping us carry our wealth from Egypt by according them a certain level of Kedusha such that a firstborn needs to be redeemed before it may be used.

The Zohar, in Parashat Bo, gives other reasons for this Misva, based on the teachings of Kabbala.

We might also suggest that this Misva alludes to the need to elevate the physical and material world. The Hamor (donkey) is commonly viewed as a symbol of Homriyut – the physical and material aspects of life, as opposed to the spiritual aspects. Judaism teaches that although these areas of life have no intrinsic value, they can and must be "redeemed" and utilized for higher purposes, at which point they indeed become very valuable and significant. The Mishna in Abot exhorts, "Ve’chol Ma’asecha Yiheyu Le’shem Shamayim" – "All your deeds shall be done for the sake of Heaven." Our religious acts are of course done for the sake of Heaven. The Mishna here refers to "your deeds," the things we do for our own needs and purposes, and instructs us to ensure that even these are done "for the sake of Heaven." Activities such as eating, sleeping and exercise are inherently physical, but can become elevated when they are done for lofty purposes. The Torah is very practical. It does not expect or demand that we deprive ourselves of the physical necessities of life. Rather, it requires us to inject them with holiness. This concept is symbolized by the Misva of Peter Hamor, as we are told that the donkey, the symbol of Homriyut, must not be left in its default state. We are to "redeem" it and elevate it through a Kohen, the symbol of spirituality. By "redeeming" the physical world, we infuse it with holiness and turn it into something sacred.

There may also be another symbolic explanation of this Misva. The nation of Yishmael believes that the highest form of devotion to G-d is killing oneself for His sake, in the process of performing what they consider to be a religious act. We, however, believe that the highest form of devotion is by living "Al Kiddush Hashem," not by dying "Al Kiddush Hashem." The Torah clearly instructs, "Va’hai Bahem" – we are to live through the performance of Misvot, not die as a result, except in the very rare circumstances when martyrdom is required. With these few exceptions, the Torah wants us to spend our lives sanctifying the Name of G-d, rather than sanctifying His Name in just a single moment by dying for Him.

This distinction between us and Yishmael, I believe, is alluded to in the story of Akedat Yishak. Abraham took Yishak to be sacrificed on an altar, an act which would follow the creed of Yishmael, which champions death for the sake of G-d. Before going to the mountain, Abraham turns to Yishmael and Eliezer and says, "Shebu Lachem Po Im Ha’hamor" ("Stay here with the donkey"), which the Gemara interprets to mean that these nations are "Domeh La’hamor" – resembling a donkey. Yishmael is symbolized by the donkey, whereas Yishak was replaced on the altar by a ram (which is in the same general family as a sheep). The moment G-d commanded Abraham to take Yishak off the altar, He determined that He wants life, not death. In essence, He chose Yishak over Yishmael; the doctrine that champions life over the doctrine that champions death.

This was the first "Pidyon Peter Hamor," as the ideology of Yishmael – the donkey – was replaced by the ideology of Yishak – the sheep.

This Misva thus commemorates Akedat Yishak, and brings to mind the merit of this great act, and the moment when G-d proclaimed that He wants us to live for His sake, and not die for His sake. Of course, anytime we invoke the memory of Akedat Yishak we bring upon ourselves Hashem’s mercy and compassion, and thus Pidyon Peter Hamor is a very significant and meaningful Misva through which we access G-d’s attribute of mercy and the great merit of Abraham and Yishak.