Tao Te Ching · Lao TzuChapter 70
My words are very easy to know, and very easy to practise; but there is no one in the world who is able to know and able to practise them.
There is an originating and all-comprehending (principle) in my words, and an authoritative law for the things (which I enforce). It is because they do not know these, that men do not know me.
They who know me are few, and I am on that account (the more) to be prized. It is thus that the sage wears (a poor garb of) hair cloth, while he carries his (signet of) jade in his bosom.
吾言甚易知，甚易行。天下莫能知，莫能行。言有宗，事有君。夫唯無知，是以不我知。知我者希，則我者貴。是以聖人被褐懷玉。