The vessels have two aspects which are interrelated:
1) The first aspect is that the vessels give form and definition to the lights. This is in order to give them defined existence. Furthermore, it is because of the vessels that a transformation from spiritual existence to physical existence takes place. For example, because of the vessel of the physical eye, the spiritual power of sight transforms from spiritual sight to physical sight. Through the vessel of the physical arm, the spiritual power of movement transforms from spiritual movement to physical movement. The physical brain transforms the spiritual ability to think so that one can think only in physical terms. It is specifically because of the vessel that a transformation from spiritual existence to physical existence, from beyond definition to definition, from infinite to finite takes place.
2) The second aspect is that the vessels limit the light. For example, the human eye limits the power of sight to seeing only so far. The physical arm limits the power of movement to the limited capability and strength of the arm. The physical brain limits the power of thought. One can think so much before he has overloaded his brain and must rest. Such is not the case with the spiritual light itself. It is unlimited. On rare occasions the unlimited spiritual light of the soul may break forth. Examples of this are the well known cases of a mother who rescues her child who is trapped under the wheels of a vehicle. With superhuman strength she lifts the vehicle and rescues the child. Another example is a person running for his life from his enemies. He will suddenly be able to run much faster and much further than he is naturally capable of. Both of these are cases of the light of the soul breaking forth in an unrestrained fashion.