Question

"the man who has devoted himself to money is a slave to it"

Answer 1

This whole answer is a guess in my opinion so ya >_<

A man who devoted himself to money would be known as a greedy man. And that he would do anything for money. So if you demanded for him to do something immoral, he will probably do it because of money. And in that sense it makes him a slave to money because he will do anything to get money.