We read in this week’s Portion the instructions given to build the Mishkan. Naturally it was necessary to have all the supplies required for this project. Where was all the money, materials, and the work to come from? Hashem tells Moshe to ask the people to contribute these items. How much was each person expected to contribute? Hashem says: KOL ISH ASHER YIDVENO LIBO, “…every man what his heart motivates him…” (Ex. 25,2)
There was no prescribed amount. Everyone gives whatever he feels he should give. In the Book of VaYikra we will read about the sacrifices that were to be given in the Mishkan. We are told specifically what each individual must give for various transgressions. When it comes to the upkeep of the Mishkan nothing is left to chance. We are told explicitly a person’s obligations. It is not left up to his heart’s motivation. Why the difference?
The Torah recognizes human nature. The Torah knows that people are ready to give money and support the building of new facilities where they can put up a plaque or some other means of honoring or memorializing a name. Upkeep, on the other hand, has no way of showing who gave the donation or who is supporting the operations. We see this when a synagogue or a school is being built. People contribute generously, but when support is needed to keep functioning it is difficult to get people to contribute.
Hence, to build the Mishkan it was not necessary to tell people what to give. When it came to keep the Mishkan functioning with the sacrifices they were given specific instructions what each individual must contribute.