Because it is clean, its brightness is also immaculate. Because of this, one who wishes to gain pure wisdom cultivates this dhyaana absorption. Furthermore, even when one is merely striving at worldly endeavors close at hand, if he is unable to focus his mind, then such endeavors will not be successful. How much the more would this be the case where one wishes to realize the extremely profound path of the Buddha yet fails to avail oneself of dhyaana absorption. Dhyaana absorption refers to the focusing of thought which has become chaotic.
Chaotic thoughts float lightly about even more readily than goose down.
They gallop along and scatter ceaselessly, moving faster than a swift wind. Their uncontrollability and unstoppability are more extreme than that of monkeys. It is the characteristic of thought to be unrestrictable and unstoppable like this. If one does wish to bring it under control, then, in the absence of dhyaana , one will be unable to achieve absorption. It is able to wash away the dust of desires.