Redemption of Firstborn Donkey
Why was the donkey the only non-kosher animal whose firstborn required redemption?
The Aish Rabbi Replies
Your question is correct that the donkey was the only non-kosher animal which required redemption. Unlike the cow, sheep and goat, whose firstborns were given to a Priest who brought it as an offering to the Temple, a donkey obviously cannot be brought as an offering. Instead, it was traded in for a lamb or a kid, which was given to the Priest in its stead (as an ordinary gift, not to be brought as a sacrifice). See Exodus 13:11-13 and Numbers 18:15-18. As Exodus 13:13 continues, if the owner refuses to redeem his donkey, its neck is broken – as punishment to the owner for his failure to fulfill his obligation.
Why was the donkey different? The Talmud asks this question as well and explains that the donkey had a special role in the Exodus (which this mitzvah commemorates – since God spared the firstborn children and animals of the Jews at the Plague of the Firstborn). Every Jew who departed Egypt took many donkeys with him to carry all the booty the Egyptians gave him right before he left (Exodus 12:35-36; Bechoros 5b).
The Midrash brings an additional reason – that the Torah equates the wicked, dissolute Egyptians to donkeys (see Ezekiel 23:20; Pesikta Zutresa to Exodus 13:13, see also Bereishis Rabbah 96:5).
Ibn Ezra (Exodus 13:13) explains the rationale behind this mitzvah and in doing so suggests a third reason why it applied to the donkey. At the final plague, God slew the Egyptian firstborns – humans and animals – while sparing those of the Jews. The only reason they deserved life over the Egyptians was because they would henceforth be dedicated to God. This is why the firstborn children were initially devoted to Divine service (until they sinned at the Golden Calf and were replaced by the Levites), and the animals were consecrated as sacrifices. A donkey could not be offered and so would be given as a gift to a Priest. If its owner refused to give it, it would have to be slain. Now that it was not being dedicated to God it no longer deserved life – to be spared from the Plague of the Firstborn – and would have to be killed.
Continues Ibn Ezra, this explains why it applied to donkeys alone. Those were the only non-kosher animals which belonged to the Jews at the time of the Exodus and which were spared at the Plague of the Firstborn. Thus, only those became obligated to Hashem.