The Reality Of The Soofees, By Ibn Al-Jawzee
Ibn Al-Jawzee said:
“Then another group of people came (afterwards) that revised the way of Soofism, characterized it with attributes by which they distinguished it (from its original state), such as: wearing old tattered clothes, hearing (music), bursting out n passionate emotions, dancing and clapping. And they particularized themselves by exceeding in cleanliness and purification.
Then this matter (Soofism) continued to flourish, and their shaykhs began to fabricate stories for them and speak about their mystical occurrences. This affirmed their remoteness from the scholars. Rather, this even affirmed their views that what they were upon was the most complete forms of knowledge, such that they named it the hidden knowledge (al-‘ilm al-baatin), while making knowledge of the religion apparent knowledge (al-‘ilm adh-dhaahir).
Among them were those whose severity in hunger brought them to fancy corrupt notions. SO they would claim strong love and passion for the truth. It was as if they imagined a figure with a beautiful appearance and thus fell madly in love with it. These individuals linger between disbelief and innovation!
Then these people divided into various orders and their beliefs grew corrupt. So among them were those who held the view that Allaah is incarnate in His creation (hulool), and those who held the view that the Creator and creation were in reality one existence (ittihaad).
And the devil did not stop speaking to them about different types of innovations until they made them into aspects of the Sunnah.”
[Tablees Iblees, by Ibn Al-Jawzee, p. 162]