When our Parsha talks about the making of the planks, Rav Elie Munk comments that the numerous repetitions of the details concerning the construction of the Mishkan are all the more surprising as the Torah usually presents its laws and historical narratives in a shorter fashion (e.g. in 10:10). The Netziv explains it in terms of the Talmudic principle: Whenever the Torah repeats a passage, it does so to add previously unstated detail (Bava Kama 64b).
Rav Hirsch interprets the repetition of the details concerning the Mishkan as an indication of Betzalel and Ahaliav’s awareness of their holy work. Every detail and minor step was done with holy meaning and symbolism. The concentration upon the underling symbolic meaning was crucial.
Rabbeinu Bachya compares the specifications pertaining to the Mishkan, which cover half of Sefer Shemot, with the laws of the sacrificial service, which are also extensive, covering more then half of Sefer Vayikra. In fact, the Torah observes that although the sacrificial laws were only relevant during the time of the Bait Hamikdash, the Torah described its laws at great length. This is an indication of the importance of the theoretical study of the sacrificial laws. Hashem considers the study of the laws of the sacrifices equivalent to actually offering the sacrifices and so He pardons the sins of those who engage in this study (Taanit 27b).
The same concept applies to the Mishkan. The diligent study of its complex concepts elevates man to higher spheres of thought. There, far from all material preoccupations, he rediscovers the spirit of holiness that filled the Mishkan and later the Bait Hamikdash. Hence, although now the Mishkan is no longer in existence, it continues to fulfill its mission. Through our study of its laws, it continues to live among us. Moreover, by insisting on repeating these laws, the Torah arouses our interest and draws our attention to the great importance of the basic ideal of a Divine dwelling place in man’s midst.
King David (Tehillim 48:13-15) expressed this thought as follows: “Walk about Zion and go around her. Count her towers, mark you well her ramparts, admire her palaces; that you may tell it to generations that Hashem is our God forever and ever. It is He who will guide us eternally.”