I think this saying refers to the fact that wealth can become all-important to some people, more important than learning about God's Will.
Many times in the New Testament, Christ talks about the fact that it is hard for people with a lot of wealth to "get into the Kingdom of Heaven." He was asked by a wealthy young man what he had to do to (rephrased) "find God", and Jesus told him to sell all his stuff and then follow Him (Jesus). The young man could not do it.
Money is nice, but it is not supposed to be the focus of one's life- especially if your possessions are more important than doing God's Will. I believe that this is what that saying mean
In verse 24, Jesus explains that it is the trusting in riches that condemns a man to not having eternal life in this particular context.