Our Gemara describes the offerings that the nesi’im brought when the Mishkan was inaugurated as Chattas Nachshon. Even though all the nesi’im brought this sacrifice, it was named after Nachshon, the Nasi of Shevet Yehuda because Yehuda was the leader and the first one to bring it.

A typical chattas is to achieve atonement for a sin committed out of ignorance or forgetfulness that would incur the kares punishment if done intentionally. According to Ibn Ezra (Shemos 29:14) The word chattas implies removal or purging, and so too the chattas offering generally cleanes from sin.

Yet there are a number of situations where a person is obligated to bring a chattas, and there is no clear sin, such as the chattas of the Nazir, Metzora, and Yoledes. There are various Midrashic explanations to identify what sins were committed. The Yoledes needs atonement because during the anguish of labor, she heretically swears to reject married life in order that she will not go through labor again (Niddah 31b). The Metzora needs atonement because there is a presumption that his disease and quarantine was due to antisocial sins such as pride, l’shon hora and miserliness (Arachin 16a). The Nazir is said to have sinned due to his extreme and excessive rejection of the normal pleasures of life. That is, though his motivations might have been to strengthen his piety and possibly appropriate (Taanis 11a), in the end this extreme behavior requires its own penance to forestall arrogance or other disproportionate reactions that come from rejecting normal life. Ramban (Bamidbar 6:14) adds an original explanation for the Nazir’s chattas: Once he committed to life on a higher level, he now needs atonement for desiring to return to the physical pleasures and indulgences.

Most fascinatingly, God too brings a chattas on Rosh Chodesh for having shrunk the Moon (Chulin 60b)

However, what can we say about the chattas Nachshon of the Nesi’im? Since they are the leaders, we can presume it is for some collective sin, but even so, ordinarily there are other sacrifices typically brought for the community such as those on Yom Kippur and Rosh Chodesh (see Mishna Zevachim 5:3) I read online a brilliant idea from Rav Boruch Weintraub on the Har Etzion website. The human foible and need to have God in some concrete place and in a concrete way is both necessary on a practical level, but also a shortcoming, and therefore a “sin”. As Shlomo Hamelech declares, and maybe even apologizes for, in Melachim I (8:27): “The heavens and The Heavens above that cannot contain You (God), and surely this abode I have built for you.”

Similarly, Sefas Emes (Pikudei 5635) says that when the Jewish people declared “we will do and we will listen” they elevated their observance beyond action. Their willingness to do even before listening brought them to a state of awareness of godliness and spirituality to an extent that they wouldn’t actually need to occupy the world of action. However, when they sinned with the Golden Calf, they lost this ability. The Mishkan became a compensation for this, allowing for more concrete, religious actions and observance. (It is actually a dispute between Rashi (Shemos 31:18) and Ramban (Vayikra 8:1) about whether the Commandment to build the Mishkan was prior or subsequent to the sin of the Golden Calf.)

Within all of us is this tension. A part of us might find the rituals confining, excessive and boring. Why must be drudge through organized prayers and rituals? Why can’t we just connect to God and be a Jew at heart? The feeling is most legitimate. However, as a matter of practicality, without the structure, observance would deteriorate for most people. We we are weak and need the concrete places to see God instead of seeing him everywhere. At the same time, we acknowledge this shortcoming with the chattas Nachshon.

One final thought to bring it all together. What does it really mean that God brings a chattas to atone for shrinking the Moon? Perhaps Midrashic the story (Chulin ibid) of the Moon lobbying before God that one cannot have two kings wearing the same crown, i.e., both the sun and the moon cannot be dominant, is metaphorically alluding to the same idea. In an ideal sense, everything should be daylight, that is everything utterly illuminated with God’s light and no darkness. Yet, the world cannot really operate in this ideal zone and there must be gaps in the light and darkness too, in order for physicality to exist. God has to acknowledge this practical truth to let the world exist, even though it also brings loss and suffering, and He too brings a chattas to acknowledge this. Yet, Yeshaiyahu prophesied (30:26) that in the messianic future, the light of the moon will be restored, which could be alluding to the idea that the practical world will transcend to an ideal existence.