In some traditions the purification of the soul is achieved through scourging. This practice is one which was advocated by Gerald Gardner, not only for purification, but also towards the achievement of a variety of altered states of consciousness. He first mentions it in High Magic’s Aid where Morven tells Olaf, after his initiation:
“Water purifieth the body, but the scourge purifieth the soul”
This seems to hark back more to the practices of the medieval Christian flagellants using self-inflicted pain to alter consciousness and ‘purify’ their souls than on cleanliness of the body itself.
The use of the scourge in the Wiccan tradition as purification also forms part of the initiation rites. Gardner’s fictional initiation account in High Magic’s Aid gives us an example of this in which the initiate is scourged forty times for this purpose:
“Thou first must be purified. Taking the scourge from the Altar, she struck his buttocks, first three, then seven, then nine, then twenty one strokes with the scourge...”
This sequence is the same as that which is found in accounts of initiation in various Books of Shadows both in published and unpublished sources.
There are also recorded examples of initiates of medieval witch coven’s allegedly being scourged by the Devil during ceremonies. In most instances it is not clear from the accounts why the scourging is taking place, other than that it might be a form of punishment for disobedience. One example is recorded in the 1678 accounts of Katherine Liddell of Scotland where it is said curious details were given including:
“that he (the devil) was cold to the touch, and his breath like a damp air, and that he scourged them oft, and was a most ‘wicked and barbarous master’…” 
Many reasons have been given for the use of forty strokes during the scourging. For instance within the tradition this number corresponds to the number of knots on a traditional scourge (8x5) which in turn equals the so called eight paths of power multiplied by the number of points on the pentagram. Scourging and flagellation have a long history of use throughout the ancient world and examples can be found from Rome, Greece and in the later Christian practices. The precedent for the use of forty strokes may be found in the Bible when St Paul said in Corinthians 11:24-25:
“Of the Jews five times received I forty stripes save one.”
The reason for the ‘save one’ is that it was illegal under the laws of the time to give more than forty strokes, hence to avoid any misunderstandings with this law, it was customary to give one stroke less. It may also be of interest to some that the person who was scourged in this way, would be tied to a low pillar for the duration of the scourging to ensure that they would be leaning forward. This practice was described by Cyprian in his third century work The Life of Cæsarius Arelatensis and seems to parallel the descriptions given by some modern authors of how some covens perform scourging during the first degree initiation rite. As an aside to this, it is curious to note that after Solomon, Cyprian is probably the most often attributed author of grimoires, including the black book Clavis Inferni, which deals with the control of the demon princes of the four cardinal directions.
 Witch Stories, Lynn Linton, 1861
Extract from: Wicca: Magical Beginnings written by d’Este & Rankine, 2008 (Avalonia.) PB / Kindle @ https://amzn.to/3Ay4HJr. Shared here with the intention to inspire and inform the now and future generations interested in Wicca and other Pagan traditions inspired by it.