there is nothing outside the heart - 心外无物

Mr. Yangming said, there is nothing outside your heart, everything is within, therefore, when you have a problem with someone, you don't have to look without, but within. 500 years later, one American doctor, Hew Len, cured tens of insane criminals by working within.

All he did is repeating this mantra:

If you think reading Chinese book difficult, try this one then
阳明先生说，心外无物，佛说，心生万物。
就是说我们心想的一切，均可事成。由于我们的妄念太多，不想要的事情，由于常常念叨，也变成了事实。
因此，与其把“心想事成”当作祝福，不如作为一个警告。
所以西人常说，be careful of what you wish for.