All The Questions are Only When the Bais Hamikdosh is Built:
The Medrash states that the scoffers of the generation mocked Moshe and said that he became wealthy from building the Mishkan (by keeping some of the gold and silver for himself). Therefore, he presented them with a complete reckoning of how everything was used.
Rav Meir Shapiro zt”l explains that much gold and silver was collected for the Mishkan and its vessels, and it was erected with much beauty and glory, but people still complained and claimed that Moshe enriched himself from the donations. However, when everyone donated gold and silver to make the eigel, which ended up being a small idol, no one complained. No one wondered what happened to the huge amount of gold and silver that was thrown in with no order and no reckoning of what was being done with it.
He says that this is the way of the world. People only ask questions when something holy is being built. At such a time, the yeitzer hara puts such thoughts in people’s heads and causes them to complain and to claim that the money was misused.
Still and all, Rav Meir offers a defense for Klal Yisroel. Chazal say (Yerushalmi Shekalim 1:1): “Yisroel is holy. When they were asked to donate for the eigel, they gave. When they were asked to donate for the Mishkan, they gave.” He says that this can be read as a question: “When asked to give for the eigel, did they give?”
In other words, they didn’t realize they were donating towards something forbidden. They were told that money was needed for a good cause, to create a way to worship Hashem, so they gave, as they thought they were giving for a Mishkan.
