In Parshat Terumah, the Torah goes into great detail describing the Mishkan's construction. However, the Parsha leaves us with a question. The question is not who built the Mishkan because we know that Bezalel was selected as Hashem's "special contractor." The question is definitely not what materials were to be used or how the Mishkan was to be constructed because the Torah spends the whole Parsha describing what was needed to build the Mishkan and precisely how to proceed with its construction. The issue is where the Mishkan was built. In order to build the Mishkan, many rare and exotic materials were needed. Included on the blueprints were items such as gold, silver, copper, linen, goat's hair, wool with purple dye, wool with blue dye, the skin of the Tachash, spices, olive oil, Shittim wood, and fourteen precious gems. If Bnai Yisrael are in the middle of a desert, where are they going to come up with all of the necessary materials?
The above items found their way into the hands of Bnai Yisrael through Hashem's divine plan. For example, all of the gold, silver, and copper came from the Egyptians. Chazal teach that during the plague of darkness, Bnai Yisroel were allowed to enter the homes of their Egyptian masters to seek out any treasure that may have been kept hidden. This way, when they left Egypt, Bnai Yisrael would know exactly what to ask for from the Egyptians as compensation for their long years of slavery. Of course, the Egyptians complied and parted with their beloved belongings. Also, Chazal teach that the sea engulfed the Egyptians at Kriat Yam Suf and more gold, silver, and copper were washed ashore in the form of the Egyptian chariots.
Many of the items listed above were also acquired through miracles. A good example would be the fourteen precious gems. When Hashem brought the Mann to a Tzadik, a righteous individual, He included special bonus features. One such bonus was that the Mann came encrusted with precious gems. Coincidentally, these precious gems were exactly the kind required for the Mishkan and the Tzadikim gladly donated them. Another good example of acquisition through a miracle was the skin of the Tachash. Hashem only created one of these unique animals, and He created it to appear in the desert exactly when Bnei Yisrael were passing through. Its multicolored coat was needed for the Mishkan.
Even the Avot had a hand in making sure Bnei Yisrael acquired all the necessary requirements for the Mishkan. For instance, a question might have aroused where Bnei Yisrael were going to find the Shittim wood. The answer, according to Chazal, lies about three hundred years earlier when Yaakov Avinu saw with Ruach Hakodesh that Bnei Yisrael would need the Shittim wood for the Mishkan. He therefore planted the seeds for the Shittim tree all over Egypt and told his children that when they left Egypt in the future, they should bring the Shittim wood with them. You may also have been wondering where Bnei Yisrael were going to find a 72 Amah (approximately 103 foot) wooden beam. The answer goes back to Avraham Avinu. He planted this tree and, in its shade, served his guests and prayed. The tree grew over time and during Kriat Yam Suf the Malachim cut it down and dropped it on the shore. Bnei Yisrael figured that such a large tree could be used for something important so they brought it with them. Sure enough, this tree was destined to be the middle beam of the Mishkan.
From here we see how Hashem takes care of everything. If He took care of such a big thing as the Mishkan, then surely He will take care of the smaller things in life as well.