ויקחו לי תרומה
מאת כל איש אשר ידבנו לבו
תקחו את תרומתי
וזאת התרומה ...
ועשו לי מקדש
- Take for me Terumah
- From every man whose heart motivates him
- Take My Termah
- This is the Terumah that you should take (followed by details of the 13 types of items) ...
- And make for Me a Mishkan
- So that I might dwell among them.
Rabbi Horowitz compared this to the question as to why the Chashmonaim needed to search for pure uncontaminated olive oil when they rededicated the Bais HaMikdash. Halachically, they could have used the tamei oil since there was no other oil available. The Avnei Nezer points out that when starting a new endeavor, one does so in the best way possible. This sets the foundation for the entire enterprise and enables it to be built up properly. This is like the education of a child. It ensures that the child will grow properly and continue to develop in the right path. The rabbi then spoke about the Choson and Kala and how the foundations that have been set by their families will affect the "bayis neeman beYisrael" that they are now in the process of building.
The Aish HaTorah printout speaks about the three languages of giving that are shown here. The first is for those who give lishmah, for the purest of motives. The reason that they give tzedakah is for love of Hashm. The second motive speaks about those people who feel sorry for the poor person that they are supporting or who are enthusiastic about the particular cause that the money will go to. THe third category is those who are embarassed to be seen not giving or who regard the money as a "tax" that they are required to give. In any case, the money is to be accepted without inquiring into the motives of the giver. The giver is appreciated for his actions and the project will end up causing the final benefit to the community as a whole.
I have seem commentaries pointing out that the most miniscule misstep at the beginning of a project can lead to major catastrophe down the road. A fraction of a degree of the proper course can result in missing the target by a massive amount after having traled a great distance. Imagine two radii of a circle. One can step from one to another easily at the beginning. However, they can end up millions of miles apart.
Update: Rabbi Sorotzkin made an interesting point. Why was the building of the mikdash accomplished through donations, while the upkeep required the tax of the Chatzi Shekel? This shows that human nature has not changed. People are willing to donate lavishly for many causes as long as the result is something visible. However, the necessary upkeep and maintenance cannot be left to donations. Rabbi Sorotzkin mentioned a major meeting of the great rabbis of Europe to get funds for the Lithuanian Yeshivos. Someone asked how com Rabbi Meir Shapiro of Lublin was able to raise so much money for his yeshiva? Rabbi Sorotzkin pointed at that once the yeshivah was built, Rabbi Shapiro would have just as much trouble raising the money for the needed food and upkeep as all the others (and that is what happened). Even Hashem could not rely on voluntary donations for the upkeep.