קל"ה - הלכות שבועות א:א
When a person is able to stay awake the entire night and break his desire to sleep he is then able to break his desire for money. As a result he is able to rely solely on Divine Providence, which is a concept of open eyes that are not threatened.
Most of the holy sparks and sunken souls are contained within money, because the essence of the scattering of one's soul happens through the desire for money. The tzaddik who is able to completely break the desire for money is able to draw all of the sunken souls that had fallen because of money. He is able to protect, gather, and uplift them to the highest holiness. By doing this, the tzaddik makes a tremendous unification in Heaven, and is thereby able to draw down Torah. Through this complete Divine Providence is drawn into the world.