In a discussion about the proper time to raise one's hands to level of one's head or above, Rabbi Hezkiah teaches that if a person does so while not in a state of prayer, his ten fingers arouse the accusing forces in the spiritual worlds. However, when utilized properly, the positioning of the hands in prayer have the potential to channel abundant divine sustenance into this world.
These ten spiritual powers are requested to receive the blessings from Above and transfer them Below to bless he that is making a blessing…(Zohar 67b)
These blessings, reflected in the ten fingers of the hands, are also like the ten sayings by which the world was created. These 10 sayings are also reflected into the expansion of 10 letters of the name of G‑d that add up to 45 and empower Zeir Anpin. From this level the power devolves onto the ten fingers of a person raising their hands in prayer.
When raised in prayer, the fingers arouse the influence of this chain of holy force….
When raised in prayer, the fingers arouse the influence of this chain of holy force. Then all the sefirot of the kelipot that connect themselves to the extremities of the fingers are made subservient to the Holy King.
The place where the body meets the external world of the kelipot and gives them a "foot hold" is at the extremity of the fingers. The fingers and toes are the furthest extremities from the seat of the soul in the mind and heart of man. The fingernails, at the outer edge of our own physical world, collect dirt in that world. The connectment of this dirt reflects the desire of the Unholy to feed off the Holy in the spiritual dimension.
This is the secret behind the bending of the fingers towards the flickering flame of the Havdalah candle….
This is the secret behind the bending of the fingers towards the flickering flame of the Havdalah candle at the ceremony marking the end of Shabbat and the beginning of the "secular" week. At this time we bend the fingernails toward the flame and look at the reflection of the flame in the fingernails while pronouncing the blessing "…Borey m'orai ha'esh" ["…He Who creates the light of the fire"]. Spiritually, the light of the candle represents the Shechinah, and the fingernails the kelipa. We look at the representation of these forces and see the flame of the holy reflected in them. We "bend" these forces to the Holy - signifying that they are nullified before its power. We recite a blessing over the light reflected in them - signifying that everything reflects the power of the holy - even in that which appears furthest away.
That the hands are an extension of our Holy soul….
The same concept, that the fingers are the place where the impure forces connect themselves, is behind the idea of washing of the hands upon rising in the morning. The purifying force of the water is poured first from the right hand over the left hand - representing the power of chesed over gevura. This signifies the removal of the residue of the external forces that manifested themselves in our sleeping and dream state. It also permeates our consciousness with the idea that the hands are an extension of our Holy soul and prepares them to be raised in purity, in prayer and supplication.
[Adapted from the RaMaK and Mikdash Melech]