Translation:He will become rich if he works diligently.
You'd like to think so, but it doesn't matter how diligently some people work. Some just have really bad luck and end up poor regardless.
Some work particularly diligently, like in a factory. They may make less than a living wage in dangerous conditions while the management become millionaires, getting obscenely rich off others who are actually creating the wealth. Communism was created in reaction to that blatant inequality. On paper it looks logical and fair compared to a system based on greed but human nature takes over when implemented. After 200,000 years we are still like monkeys in trees trying to work something out.