Thought is interior speech; and as you converse with each other by words, so may you converse with, demand, and command the Inner “Presence” through thought. Thought can be made a dynamo by which you can charge the body, home, condition, or activity according to the consciousness or understanding you have of its power.
This brings Me to one of the vital points for all Students, and that is to break the habit of thinking out loud. One has but to watch himself to see how often he is unconsciously expressing the thought out loud. This has to be positively overcome before certain Instruction and Information can be given. Why? Because this habit of the human is a lack of controlled energy; if the person is in the possession of secret Information, in an unguarded moment he will reveal It. I wish each one to take him or herself firmly in hand on this particular point. Do not even in the simplest things in your daily activity allow the thought to be expressed in words, as though talking to yourself.
More Students have fallen down on this particular point than any other one thing. A few days of watchful care will entirely overcome such a habit. The outer is but a conglomeration of habits. In the Garment of the Student who has entered the conscious Path is placed a Cloak of Protection of Thought. In talking to oneself, the worded expression breaks through this Garment of Thought, and the Student wonders why he does not make more progress. It is because he has caused a leak in the Fountain of Wisdom. Thought is truly the Activity of the Soul of the God-man, the bringing into Activity that Mighty Presence of Energy which may be qualified by thought to any Height of Sustaining Power and Intelligence.
Ascended Master Instruction, The I AM Discourses Vol 4.
Silence! Peace! And Obedience to the Mighty I AM Presence forever.
Adorations & Affirmations, The I AM Discourses Vol 5.