《淮南子·缪称训》
内心形成情感而不吐露、有真情而不流露在外，这种情况还没听说过。
含而弗吐，在情而不萌者，未之闻也。
That there should be the feeling within and no manifestation of it, and the reality without but no manifestation of it, - this I have not yet seen.