Tao Te Ching: Chapter 81
Sincere words are not fine; fine words are not sincere. Those who are skilled (in the Tao) do not dispute (about it); the disputatious are not skilled in it. Those who know (the Tao) are not extensively learned; the extensively learned do not know it.
The sage does not accumulate (for himself). The more that he expends for others, the more does he possess of his own; the more that he gives to others, the more does he have himself.
With all the sharpness of the Way of Heaven, it injures not; with all the doing in the way of the sage he does not strive.