سلطان طریقت و برهان حقیقت
ابو محمد سهل بن عبدالله التستری (شوشتری)
Abu Muhammad Sahl bin Abdullah Tustari
(203-283 / 818-896)
(قدس الله سرّه)
They asked Sahl bin Abdullah, what is the sign of misfortune? He said: It is that He gives you knowledge but does not give you success in acting upon it, and He gives you success in action but does not give you sincerity, which makes your actions in vain, and gives you companionship of the pious but does not give you acceptance in the heart.
پیر هرات، شیخ الاسلام
خواجه عبداللّه انصاری هروی،
در طبقات الصوفیه.