Torah from Benjy's Room

While snooping around my little brothers room today I found the following piece of Torah.

Shemos 38:21 "These are the accounts of the Mishkan"

After reading through the beginning of this past weeks Parsha, you will read something rather peculiar. Why did Moshe only render detailed accounting for the silver? Didn't people also donate gold and copper?

R' Yonason Eibeshutz answers that Moshe specifically had to count the silver because the gold was derived from voluntary donations while the silver consisted of half shekels that every Jew had to bring. Moshe felt that some people who had made the obligatory donation may have been skeptical and therefore demand an exact accounting of what had been done with their money, but generous individuals who had made voluntary donations of gold would not be so petty as to insist on such a report.