Parshat Naso presents an array of laws, including those of the Nazir. The Nazir can be any man who wishes to draw closer to Hashem and attain a higher level of Kedushah. In order to maintain this level of Kedushah, the Nazir is not permitted to drink wine, cut his hair, or become Tamei Meit (impure through contact with a dead body).
It is interesting to note that the Torah forbids the Nazir to attend the funeral of his mother, father, or any of the seven family members that a regular Kohen, who is also forbidden to become Tamei Meit, is allowed to attend. This puts the Nazir on the level of the Kohen Kadol, the high priest, demonstrating to Bnei Yisrael that even if they are not from Sheivet Levi, they can still attain such high levels of Kedushah.
This Kedushah comes at a price, however. The Torah states that if someone dies suddenly in close proximity to the Nazir, he must shave his head and bring several offerings, including a sin-offering, in the Mishkan. His original Nezirut is nullified, and he must rededicate himself, because “he sinned regarding the dead person.” This expression is very puzzling; after all, it was not the Nazir’s fault that the man died and made him Tamei! Why does the Torah say that the Nazir sinned and obligate him to bring a sin-offering?
Perhaps the Torah is trying to show us that another attribute of the Nazir is caring for the rest of Bnei Yisrael. As Chazal say, “Kol Yisrael Areivim Zeh LaZeh,” all Jews are responsible for one another. The similarity of the Nazir to the Kohen Gadol may indicate that the Nazir should attempt to imitate Aharon, the Kohen Gadol in the desert generation, who went to great lengths to restore peace between quarreling Jews. Even though the Nazir who became Tamei did not do anything actually wrong, he may have neglected to show the kind of care that Aharon would have – to be constantly on the lookout for a Jew in need of aid. Along with the rest of the elements of Kedushah comes a requirement to look for ways to help others beyond the letter of the law. In this sense, the Nazir did not fully keep to the standards he attempted to set for himself (otherwise a Jew would not have died suddenly in his presence), and hence must bring Korbanot to atone for this slight “sin.”