In Parshat Naso, we find the third and final account of the building of the Mishkan. The first account appears in Sefer Shemot and the second appears in Sefer Vayikra. As the Torah does not unnecessarily repeat itself, each of these accounts must communicate a particular message.
Sefer Shemot speaks of the meeting between Am Yisrael and Hashem. As such, the Mishkan account can be understood as the nexus of that meeting. Hashem instructs Am Yisrael to construct a Mishkan so that He may dwell in their midst. Sefer Vayikra concerns itself with the laws of the Kohanim and is therefore referred to as Torat Kohanim. Since the Kohanim worked in the Mishkan, it stands to reason that the Mishkan should also appear in Sefer Vayikra.
Why is the Mishkan included in Sefer Bemidbar, which relates the accomplishments of Am Yisrael? Rav Kook explains that the answer resides in the wording of the account. “The princes of Israel, the heads of the families, that had carried out the census, came to the Mishkan. They brought with them sacrifices” (Bemidbar 7:2-3). The Torah then provides a lengthy description of each of the sacrifices brought by the twelve princes, despite the fact that each prince brought the same sacrifice. The Parsha then concludes, “This was the dedication of the Mishkan on the day that it was anointed by the princes of Israel” (Bemidbar 7:84).
From this it appears that the princes’ sacrifices constituted the final act of the dedication of the Mishkan. The Mishkan became functional with their contribution. What made these sacrifices so significant? The Mishkan was always associated with the Kohanim whose domain it was and who acted in its service. But Rav Kook explains that the Mishkan really belongs to all of Am Yisrael. The princes of the nation represented the political aspirations of Am Yisrael, and this aspiration is equally valid and relevant to the Mishkan as the Divine inclination of the Kohanim. The Mishkan was fused with both a spiritual and a civil (political) dimension. This fusion is substantiated by the Parsha wherein the princes brought sacrifices to the Mishkan. Not only did they actively participate in the dedication of the Mishkan, the Mishkan was deemed completed by their sacrifices. It is when the two forces within the nation join, the spiritual and the political, that we create a true home within which Hashem can reside.