Cassiel (Hebrew קפציאל Qafsiel Kaziel) meaning "Speed of God" is the Latin name of an archangel in post-biblical Judeo-Christian religion, particularly that of the Kabbalah. Unlike many other angels, Cassiel is known for simply watching the events of the cosmos unfold with little interference. He is the angel of solitude and tears, and is said to preside over the deaths of kings. 
He is often included in lists as being one of the seven archangels and often associated with the Seventh Heaven.
In the magical text Berit Menuchah, Cassiel is associated with Kefitzat Haderech, the ability to travel quickly through space. Magic spells using his name are cast to create destruction, to scatter crowds, to cause a person to wander aimlessly, or to fall from a position of power.
Ancient Hebrew amulets bearing his name are used to drive away one's enemies. The words on the charm are written with the blood of a bird and then tied to the foot of a dove. The dove is then set to flight, taking one's enemy with it. Should the bird refuse to fly, it is a sign that one's enemies won't depart either.
Archangel Cassiel can also be called: Casiel, Cassel, Castiel, Cas, Cass, Casitiel, Castael, Mocoton, Kaziel, kafkiel, Qafsiel, Qaphsiel, Qaspiel, Quaphsiel. He is also known as the angel of temperance.
In the Jewish Kabbalah
In rabbinic literature, the Kabbalah is the only text to relate the identity of angels with souls. Tradition differs as to how many classes of angels exist although all relate the number of angel classes to the heavens in a one-to-one ratio. One of the older and most common views, divides angels into seven classes. Another tradition states that there are only three true archangels and only three heavens. And then there is a third tradition, combining the two aforementioned for a total of ten classes of angels. Yet another theory relates the names of the archangels to the planets. Archangels are also referred to as the "chief angels" and called the "angels of the presence."
Archangels are connected to a level of sephiroth; the Kabbalah contains 10 levels of sephiroth each holding different meanings and responsibilities. Each sephirah is assigned a name and number and becomes associated with an archangel, a name of God, an angelic order, and a planetary force. These levels are sometimes referred to as Vessels of Light because they are representative of the progression of the realms in which they are connected. The sephiroth are God's means of interacting with the physical world.
In popular culture
- Cassiel is the main protagonist in The Outcast Season series by Rachel Caine.
- The character of Cassiel appears in Wim Wenders's film Wings of Desire, as well as the U.S. remake, City of Angels. Cassiel, played by Otto Sander in the original and Andre Braugher in the remake, watches with considerable ambivalence as his friend becomes human. In the sequel Faraway, So Close!, Cassiel himself becomes human. Nick Cave wrote "Cassiel's Song" as part of the music for that film.
- In the television show Supernatural, the character Castiel, is an Angel of the Lord. Despite being purportedly based on Cassiel, Castiel is more associated with Thursday as opposed to Saturday like Cassiel. He first appears in season 4 of the show. He also wears a trenchcoat and fights for the survival of Heaven along with aiding the protagonists, Sam and Dean Winchester.
- In the mythology of Jacqueline Carey's Kushiel's Legacy series of novels, Cassiel is one of the angels who follow the Blessed Elua in his wanderings.
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- Caine, Rachel. "The Outcast Season Series". The Outcast Season Series. ROC. Archived from the original on December 23, 2010. Retrieved October 3, 2015.
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