Thirty days after the birth of a first-born son the father is commanded to “redeem” his child by performing the Pidyon HaBen ceremony. The father gives a Kohen five silver coins, makes two brachot, and then spends a fortune on a lavish meal. While the commandment to redeem the firstborn is found in Shemot [13:13], the first actual recorded Pidyon HaBen is found in Parashat Bemidbar [3:46-51]. Moshe is commanded to count the Levites, to count the first-born, and then to exchange the two [Bemidbar 3:45]: “Take the Levites instead of all the firstborns among the children of Israel and the Levites’ animals instead of their animals, and the Levites shall be Mine.”
After all the counting was over and done, there were two hundred and seventy three more first-born than there were Levites, and so Moshe was given the following instructions [Bemidbar 3:46:48]: “As for the two hundred and seventy three of the children of Israel who require redemption, who are in excess of the Levites, take five shekels per head… Give the money to Aharon and his sons, in redemption for the firstborn who are in excess of them”. Voila – Pidyon HaBen.
A number of things about this whole first-born-for-Levite-exchange are troubling. First of all, why were the first-born chosen in the first place? What were they chosen to do? What did they do to warrant having their status transferred to the Levites? And finally, why were the first-born redeemed for specifically five shekels? The original commandment in the Book of Shemot does not mention any particular price.
The Seforno gives us some direction with a somewhat lengthy explanation on Bemidbar [3:13]: “The Temple service used to be the duty of the respective firstborn in each family. At the time when the firstborn in Egypt were killed, the Jewish firstborn had been guilty of death also, as had been the firstborn of that entire generation. They were singled out for this penalty as they were the most honoured people of their time, and as such served as role models for others. Hashem, in sanctifying them, placed them on a spiritually elevated pedestal so that they would not partake in all manner of secular pursuits, and therefore justified sparing them at that time. Due to the sin of the golden calf (egel) they had forfeited this spiritually elevated status. They had to be “redeemed” in order to resume life on a more mundane level than that for which they had been destined and their holiness was transferred to the Levites.”
Let’s summarize the Seforno:  The first-born were destined to serve as religious leaders, just as in every other religion, but  the first-born sinned at the egel and forfeited their special status, which was then transferred to the Levites, who did not sin at the egel. As for the five-shekel cost of redemption, the Seforno is silent but Rashi is not. Quoting from the Midrash, Rashi says that “Such was the sale [price] of Joseph, the firstborn of Rachel”.
The Seforno’s explanation is difficult from so many different perspectives:
 Modern man finds caste systems distasteful. A person should be afforded status according to his actions and not according to some “class” into which he is born and over which he has no control. Just because many ancient religions gave the first-born special status, why should the Torah give them the same precedence?
 Where does it say in the Torah that the first-born lost their special status because they sinned at the egel? When the Torah punishes or rewards someone, the cause for the punishment or the reward is usually clearly mentioned. For instance, after Pinchas avenges Hashem’s honour, Hashem grants him Priesthood, saying [Bemidbar 25:13] “because he was zealous for Hashem and atoned for the children of Israel.” Similarly, after Moshe hits the rock instead of speaking to it Hashem tells him [Bemidbar 20:12] “Since you did not have faith in Me to sanctify Me in the eyes of the children of Israel, therefore you shall not bring this assembly to the Land which I have given them”. But nowhere does it say “The first-born blew it with the egel and so they must be redeemed”. The opposite is true: Am Yisrael were first commanded to redeem the first-born before the Egyptian exodus, long before they sinned with the egel.
 What is the connection between redeeming the first-born and the selling of Joseph? Joseph was not sold as an act of redemption – he was sold because it was better than killing him, which is what his brothers had originally intended to do. The fact that Joseph was the first-born of Rachel seems to be a non sequitur. Yaakov had three other wives each with first-born sons who were neither redeemed nor sold into slavery. Joseph was the exception, not the rule.
The Netziv of Volozhn comes to our rescue. In Parashat Bechukotai the Torah discusses “erechin” — “valuations” — when a person donates “his own valuation” to the Beit HaMikdash. How much is a human life worth? It turns out that a person’s worth is a function of only two parameters: his gender and his age. A male, from thirty days old until his fifth birthday, is valuated at five shekels of silver. After his fifth birthday his valuation rises to 20 shekels and when he turns 20 it increases to 50 shekels. As this is the only discussion in the Torah in which a dollar-figure is put on a human life, the Netziv concludes that this must be the source of the five-shekel redemption of the first-born. The Netziv continues by questioning his own logic: if a 1-month-old child is worth five shekels, what happens if for some reason the Pidyon HaBen is delayed until the child turns 5-years-old? Does he now have to give 20 shekels to the Kohen?
The Netziv answers with one line that is well-worth remembering: “This is the way of the Torah: the essence of a mitzvah – its rationale and its details – is always supra-rational (chok).” The Netziv continues by proving his thesis: Why is a child redeemed only after he is 30-days-old? Why not perform the mitzvah immediately? According to the Talmud, the human gestation period is either nine months or seven months. A child born after eight months in the womb will not survive for more than 30 days. He is called a “nefel”. A baby must wait for 30 days until he can be redeemed in order to ensure that he is not a nefel. What happens, asks the Netziv, if we are absolutely certain that this child was born after nine months in the womb. Perhaps the mother was hospitalized immediately after conception, such that ensuing marital relations were impossible. Does this child also have to wait 30 days for his Pidyon HaBen? The Netziv answers unequivocally: yes, he does. The Torah, while eminently reasonable, defies reason.
Now let’s return to the questions we asked above.
 A first-born child is not spiritually different than his younger brothers. There is no spiritual Caste System This is the way of the Torah.
 The redemption of the first-born demonstrates that a person’s spiritual status is determined completely and entirely by the Torah. While it is closely related to one’s adherence to the Torah, there is more that is hidden than is revealed. At the end of the day the Torah decides who serves in the Beit HaMikdash and who does not. The Levites serve in the Beit HaMikdash because the Torah commands them to do so. We have stated numerous times in these shiurim that the Levites were chosen to serve in the Beit HaMikdash because of the unbridled passion in their tribal DNA. But perhaps there are other reasons that we may never understand. This is the way of the Torah.
 The five-shekel cost of redemption is also supra-rational. It can be explained but never completely understood. This is the way of the Torah. Human logic is welcome in our attempt to understand Hashem’s Torah, but it must never get in the way of the Torah.
Ari Sacher, Moreshet, 5776
Please daven for a Refu’a Shelema for Moshe Dov ben Malka.
 A comment attributed to the Seforno addresses this question: “We must not make the mistake of thinking that seeing that this verse was written before the sin of the golden calf… On the contrary, the “redemption” of which Shemot [13:13] speaks was only in order to permit these firstborn to also pursue a regular lifestyle when they would not be performing service in the Temple. Without “redemption” every object that has been sanctified is out of bounds for any mundane use whether passive or active, as it would constitute a demeaning of its holiness.”
 For some reason the Netziv asks about the case in which the child waited until he was twenty before his Pidyon HaBen, even though the question is equally relevant for the child turning five.
 The physiological accuracy of this concept is most definitely a topic for another shiur.