Kiddushin 58 - Money from the Sale of Forbidden Objects
There are many items, such as meat cooked in milk, that are prohibited not only to eat, but also to use. Thus, their value
is intrinsically zero. If one uses such an item to betroth a woman, she remains free. We listed these items earlier.
However, if he does (illegally) sell such item, then
the money that he receives from this sales is not prohibited. If he now betroths a woman with this money, she is bound to him. How do we know that?
Regarding idolatry it says
"You shall not bring it into your house and become banned like it."
This means that whatever you generate from the sale of idols is forbidden, but if you sell other prohibited items, that money is permitted.
But how do we know that this indeed is an exception? Perhaps, just the opposite, it teaches us a general rule, and any time one sells a prohibited item,
that money is prohibited as well? - The end of the phrase states, "since it is taboo." The word "it" is extra. It teaches us
that only "it" is taboo, but not the money from the sale of other prohibited items.
There are yet other items which are dedicated to a special use, which are not prohibited, and so one can use them to betroth a woman. For example, it can be
Kohen's portion of the crop or ashes of the red heifer. Still, what value to they have, if one is not suppposed to use them? Some say that even though
a regular Israel cannot eat the Kohen's portion, but he can receive a token amount for giving it to a specific Kohen, and this is the value he uses for betrothal.
Others say that this will only work for money inherited by a grandson of a true Kohen, who himself is not a Kohen, because his father is a regular Israel.
Art: Terracotta Idols Of Tabasco, From The Ancient Cities Of New-Mexico by Claude Joseph Desire Charnay