Here's a little trivia:
Another Catholic doctrine that has nothing to do with the Bible is commutation.
A principal contributing factor was money. Paralleling the rise of indulgences, the
Crusades, and the reforming
papacy was the economic resurgence of Europe that began in the 11th century. Part of this tremendous upsurge was the phenomenon of commutation, through which any services, obligations, or goods could be converted into a corresponding
monetary payment.
There used to be a small pool in the Catholic churches where the members would throw money in for indulgences. When the church was empty, the priests used a special rake to get the money out. It is where we get the term,
raking in the dough. Another not Biblical, but Catholic dogma.