The freshness of air, the quiet of environment, and above all the purity of the mind, are all so much more in the early morning that meditation comes more easily and more quickly and more naturally at such a time. But the objection is often made by Western man that he rises under the pressure of preparing for and travelling to his work, so that strain and preoccupation and clock-watching interfere with meditation and make it unsatisfactory. Even the obvious remedy of retiring earlier and rising earlier has some disadvantage because of the colder morning temperature. Against this is the great advantage of sounding a keynote for the whole day by quieting and directing the mind at its beginning.
-- Notebooks Category 4: Elementary Meditation > Chapter 2: Place and Condition > # 15