Tao Te Ching – Lao Tzu – chapter 59

In caring for others and serving heaven,
There is nothing like using restraint.
Restraint depends on giving up one’s own ideas.
This depends on Virtue gathered in the past.
If there is a good store of Virtue, then nothing is impossible.
If nothing is impossible, then there are no limits.
If a man knows no limits, then he is fit to be a ruler.
The mother principle of ruling holds good for a long time.
This is called having deep roots and a firm foundation,
The Tao of long life and eternal vision.