The Buddha also proved the existence of causality in the sutras through the following example. It seems that some people can never become wealthy, no matter how hard they try. There is nothing wrong with the way they work or operate, but they remain poor their whole lives. Others enjoy fabulous wealth throughout their lives without having to work hard for it. The same also happens with people’s health and life span. We may think that these seemingly unreasonable outcomes are due to the variable external environment, but they are not. For example, once a Tibetan king, wanting to help the poor, divided all the wealth of the nobles evenly among the poor three times. However, after some time, everything went back to where it was—the poor remained poor, the nobles stayed noble and well-off. The king could do nothing more. Actually, not all those nobles were smart and capable, the poor foolish and lazy. Most likely, in this case, it could be the workings of cause and effect. Of course, the example is not saying that we are all destined to be rich or poor, so the rich would never need to work for anything and the poor would labor to no avail. Nevertheless, the law and the workings of cause and effect are present in this example.

- Quote from The Right View, "On Cause and Effect"