Self-Control...

When the mind and body are restless, nothing in life can be accomplished.
Success is the result of control.

Bowl of Saki, by Hazrat Inayat Khan

Commentary by Pir-o-Murshid Inayat Khan:

When a person allows himself to be disturbed, that shows that his concentration
is not good. And if his concentration is not good, that shows that his will
power fails him. The best way, therefore, to protect oneself from disturbance is
to develop the power of concentration, so that the will power develops naturally
and one is able to withstand all the disturbances which arise when one has to
live in the midst of the crowd.

Independence is achieved by indifference. It does not mean that one should take
no heed of what anyone does or says; it only means one should discriminate
between important and unimportant things of everyday life; that every necessary
and unnecessary thing should not demand so much of one's attention, thought, and
feeling. Political economy has become a subject of education, but spiritual
economy is the main thing in religion. All one says and does and all that one
thinks and feels puts a certain strain upon one's spirit. It is wise to avoid
every risk of losing one's equilibrium. One must stand peacefully but firmly
before all influences that disturb one's life. The natural inclination is to
answer in defense to every offense that comes from outside, but in that way one
loses one's equilibrium. Self-control, therefore, is the key to all success and
happiness.

Another sign of progress is that, at times, one begins to feel peaceful. This
may increase so much that a restful feeling comes in the heart. One might be in
the solitude, but even if one is in a crowd, one still feels restful. Life in
the world is most exciting; it has a tiring effect upon a sensitive person. When
one is restless, the conditions in life can make one experience the greatest
discomfort, for there is no greater pain than restlessness. If there is any
remedy for the lack of peace, it is spiritual progress. Once peace is developed
in a soul, that soul feels such a great power and has such a great influence
upon those who approach it and upon all upsetting conditions and jarring
influences coming from all sides. Just as water makes the dust settle down, so
all jarring influences settle down under the feet of the peaceful.