تحفة النظار في غرايب الامصار وعجايب الاسفار 13.111: ذكر الشيخ جلال الدين.

This shaykh was one of the great saints and one of the unique men of his age, with famous miracles and great deeds, and he was one of those who live to a great age. He told me, God have mercy on him, that he had seen the caliph al-Mustaʿṣim bi-llāh the ʿAbbāsid in Baghdad and was there when he was killed. His companions told me after this time that he died at the age of one hundred and fifty, and that

for about forty years he had fasted continuously, not breaking his fast except after ten days of unbroken fasting. He had a cow on whose milk he broke his fast, and he would stand in prayer the whole night. He was thin of body, tall, with a sparse beard. The people of those mountains embraced Islam at his hands, and that is why he lived among them.