CHINESE ORIGINAL
知者不言，言者不知。
塞其兑，闭其门，挫其锐，解其分，和其光，同其尘，是谓玄同。
故不可得而亲，不可得而疏；不可得而利，不可得而害；不可得而贵，不可得而贱。
故为天下贵。
ENGLISH · JAMES LEGGE, 1891
He who knows (the Tao) does not (care to) speak (about it); he who is (ever ready to) speak about it does not know it.
He (who knows it) will keep his mouth shut and close the portals (of his nostrils). He will blunt his sharp points and unravel the complications of things; he will attemper his brightness, and bring himself into agreement with the obscurity (of others). This is called 'the Mysterious Agreement.'
(Such an one) cannot be treated familiarly or distantly; he is beyond all consideration of profit or injury; of nobility or meanness:--he is the noblest man under heaven.
READ IN CONTEXT
Self-cultivation
Begin with the way you attend to your own life: quietness, humility, honesty, and the patient work of knowing yourself.
Self-cultivation