《易传·彖传上·否》
内阴柔，而外阳刚；内柔顺，而外刚健；内为小人，而外为君子。
内阴而外阳，内柔而外刚，内小人而外君子。
Gentle and soft inside, and vigorous and strong outside; soft and docile inside, and vigorous and strong outside; small person inside, and Junzi outside.