In this week's Torah portion, the Torah commands the kohanim not to become טמא (ritually unclean) and the Sages of Chazal interpret it as a commandment to the entire nation of Israel. From this commandment we learn that the kohanim represent all of the people of Israel and the work that they perform in the Temple they do for our benefit.
The parsha opens with a command to the kohanim not to become ritually unclean by coming in contact with the dead. "And the L-rd said to Moshe, ‘Say to the kohanim the sons of Aaron and you should say to them that their soul should not be defiled among their people’." Strangely, although the commandment is intended for the kohanim only, and they are the ones whom Moshe actually commanded, the Sages of Chazal learn from here that this law applies to the entire nation of Israel, and not only to the kohanim.
As the Sages teach us in Tractate Yavamot: " ‘Say, and you should say’- to warn the great ones about the little ones". Meaning, that because the word “say” is doubled in the pasuk it is a warning for the great ones (the kohanim) to make sure that the small ones (the entire nation) do not commit a sin. Although the verse deals with the impurity that may befall kohanim, it is a general lesson to us on educating our children.
Adults have a duty to take care to distance children from forbidden things, and to prevent them from following a bad path. Therefore G-d says to Moshe with the double wording "Say - and you shall say": Tell the adults to behave this way themselves, and "tell" them that the commandments they are given, they should pass on to the next generation.
But it is still not clear why the Torah wrote such an important commandment - one which deals with the education of the next generation and concerns us all - within a mitzvah that belongs only to the kohanim. From this also arises a general question: In the Torah there are many commandments that pertain only to the kohanim, why did G-d see fit to include these commandments in the Torah, and not write a special book with laws for the kohanim which are intended only for them?
The simple answer is that since the kohanim are emissaries of the people of Israel who perform their work in the Temple on behalf of the entire nation, in any case every Jew has a share in the work of the kohanim. Therefore, when we learn about the commandments of the kohanim we are learning about commandments that are actually ours, but that in practice are only performed by kohanim.
But a more profound answer is that it says in the Torah that the whole nation of Israel is a "kingdom of kohanim" in relation to the nations of the world, and therefore, although in practice these commandments are given only to the kohanim, ideologically all the commandments of the kohanim pertain to us as well. Because just as the kohanim have a special role which they play in the name of the people of Israel, so too the nation of Israel are messengers of the entire world and we have a role to be the “kohanim” of the world spiritually, and to elevate all of the nations to a place closer to G-d.
This also seems to be one of the reasons why the Book of Vayikra is also called "Torat Kohanim" even though it has many commandments that belong not only to the kohanim but to the entire people of Israel, such as: forbidden foods, incest, festivals, shemita, yovel and more. This is because when Sages called the Book of Vayikra "Torat Kohanim" they did not mean that the book deals only with the laws of the kohanim who serve in the Temple, but that it deals with the sanctity of the entire people of Israel.
We have a special role in leading the world to its destiny, so we have special mitzvot and obligations, described in Sefer Vayikra - the “Torat Kohanim", so that we can successfully fulfill our historical role of bringing the world to spiritually elevation.
Rabbi Shlomo Sobol is the head of the Barkai Rabbinical Organization and the rabbi of the Shaarei Yonah Menachem community in Modi'in