The Truly Wealthy Person

Why would Moshe open a fundraising appeal for the Mishkan by talking about Shabbos? And why does he say that for six days work "may be done," in the passive, as if it gets done by itself? Rav Shlomo Ganzfried, the author of the Kitzur Shulchan Aruch, reads the wording as a lesson about our income, and about what it means to be rich. The Chofetz Chaim makes it vivid with a mashal of a bucket of water and a man working very hard to fill it.