Rashi notes the juxtaposition of Mishkan/Mishkan, which he explains refers to the two Temples which were taken from us. In a play on words, the word Mishkan is pronounced Mashkon, which is a pledge, collateral, security. This suggests that the two Temples/Mishkanos were taken as collateral for Klal Yisrael’s sins. At the time in which we will sincerely repent, they will be returned to their former glory. It seems strange that the destruction of the Batei Mikdash is alluded to specifically at the juncture that the Torah addresses the completion of the Mishkan’s construction. Surely, there could be another, more appropriate, place to make note of the destruction of the Batei Mikdash.
Horav Aizik Ausband, zl, derives from here that the hashroas ha’Shechinah, the fact that the Divine Presence rests among us, was a complete and irrevocable gift to the Jewish People. Thus, even when they sin and warrant an end to this glorious relationship, Hashem does not “rip up” the contract and leave us hanging. No, it is very much like a mashkon, whereby Hashem takes the Mishkan as collateral until that time that we reverse ourselves and repent. A mashkon can be seized only by the lender from the individual who rightfully owns it. He does not take a mashkon from just anyone, only from its owner.
The Torah is teaching us that, as the Mishkan is completed and Hashem is about to rest His Divine Presence among us, the Mishkan becomes our possession unilaterally. When Hashem destroyed it, He was only using it as collateral. When we repay our “debt,” we will get it back. One frightening lesson can be derived from this concept. After all the years of misery, bloodshed, pogroms and holocausts; after we have soaked the soil of Europe with our blood and our tears have created a river, it seems that we have not yet repaid the debt.