Meditation requires a positive, aggressive attitude of mind at its beginning. Because the mind may be tired at the end of the day, it cannot be forced. This is one reason why meditation requires patience. If the student waits for a while, the mind will refresh itself and get its second wind, so to speak, but most students give up before this point is reached. When the mind has refreshed itself, one is then conscious of this hitherto dormant energy and his thoughts are automatically stilled. The point has then been reached where he may release all further effort and humbly wait for the Overself to reveal itself. Warnings and voices may be experienced. Remember what the Psalmist said: "Be still and know that I am God."
Sometimes the Overself reveals itself in other ways: it may use another person, or other persons; it may appear in a sentence in a book opened at random.
One should never try to grasp the Overself. One must learn how to wait humbly for its self-revelation. With practice, this comes in a shorter time. It may last only a few minutes. After it has revealed itself and silently left, there is no need to continue or prolong meditation, except to remain for a while in the ineffable sense of peace it usually leaves behind.
It is because of the effort in mind-concentration required that morning meditation is usually recommended. Thoughts are like unruly horses: it is easier in the morning, when the mind is fresh, to control them than at the end of a day's work when the mind is fatigued.
-- Notebooks Category 4: Elementary Meditation > Chapter 2: Place and Condition > # 347