I heard on Shevat 7, January 18, 1948, Tel-Aviv
A thought is a result of the desire. A person thinks of what he wants. He will not think of what he does not want. For example, a person never thinks of his day of death. On the contrary, he will always contemplate his eternity, since this is what he wants. Thus, one always thinks of what is desirable for him.
However, there is a special role to the thought: It intensifies the desire. The desire remains in its place; it does not have the strength to expand and perform its action. Yet, because one thinks and contemplates a matter, and the desire asks the thought to provide some counsel and advice to carry out the desire, the desire grows, expands, and performs work in actual practice.
It turns out that the thought serves the desire, and the desire is the “self” of the person. Now, there is a big self or a small self. A big self controls the small selves.
He who is a small self and has no control at all, the advice to magnify the self is through the persistent thought of the desire, since the thought grows to the extent that one thinks of it.
And so, “His law will he contemplate day and night,” for by persisting in it, it grows into a big self until it becomes the actual ruler.