Chapter XIV (j)
They are the followers of Sahl b. Abdullah Tustari. He was a great and venerable Sufi, as has already been mentioned. There are many strange Karamat (miracles) vouchsafed to him which intellect fails to comprehend. His doctrine inculcates endeavor and self-mortification and ascetic training, and he used to bring his disciples to perfection through self-mortification.
It is well-known that once he said to one of his disciples to recite continuously Allah, Allah, Allah for the whole day. Next day and the following days he told the disciple to perform the same recitation until he became habituated to that dikr. Then he bade him to repeat the same performance at night, until the dikr became so familiar that he uttered them even during his sleep. Then he guided him not to repeat it any more, but let all his faculties be engaged in dikr (remembering Allah). The disciple did this, until he attained the state that he would always found absorbed in the dikr of Allah.
Some Sufi Sheikhs have said,
ذكراللسان غفلة وذكر القلب قربة
“dikr by tongue is cause of heedlessness and dikr by heart is cause of presence with the Truth”.
One day, when the disciple was sitting in his house, a piece of wood fell on his head and the injury caused bleeding. The drops of blood started trickling on the ground and drop which landed on the ground would demonstrate inscription الله, الله, الله (Allah, Allah, Allah).
The path of the Sahlis is to educate disciples by acts of self-mortification, and austerity and that of Humdunis (Qassaris) is to serve and honor dervishes. The path of Junaidis is to keep watch over one's spiritual state.
Self-mortification and devotion is the name of complete resistance to the nafs (lower soul), and until a man knows his lower soul his self-mortification and devotion are of no use to him. I will now explain the knowledge and true nature of the nafs (lower soul), so one should know what nafs (lower soul) is? And in the later part the doctrines of all sects concerning self-mortification and its principles would be elaborated, so that both are amply manifested to the seekers of the Truth.