The Midrash Tanchuma tells us that these wooden planks were actually the result of Yaakov Avinu’s foresight. He anticipated that his descendants would one day erect a Mishkan. Aware that such lumber did not exist in the wilderness, he brought them with him to replant them in Egypt. He instructed his children that when they would be liberated from the Egyptian exile, they should take these trees along with them. Yaakov taught his children that the future edifices of Klal Yisrael must be built upon the foundations of the past. We must keep in mind the mesiras nefesh, devotion to the point of self-sacrifice, of our ancestors as we build for our children. The dedication of those who lived before us should serve as a beacon of light to guide and inspire us.
We suggest another reason for Yaakov’s decision to bring along the the shittim trees. Yaakov sought to underscore the importance of hakoras ha’tov, appreciation/ gratitude, for what others have done for us. All too often we conveniently forget who has helped us when we needed it most. We must always remember the origin of the atzei shittim, as well as the mesiras nefesh involved in transporting and caring for them. With this in mind, we will view every aspect of the Mishkan, which is a microcosm of the world, as a source of Hashem’s beneficience. We will then be imbued with a sense of hakoras hatov to Hashem for all that we receive from Him. What better foundation blocks could there be for any edifice than the attribute of hakoras hatov?