Columbia subject headings:
Asceticism--Islam--Early works to 1800.
Religious life--Islam--Early works to 1800.
Harvard subject headings:
Asceticism--Islam--Early works to 1800.
Religious life--Islam--Early works to 1800.
Princeton subject headings:
Asceticism--Islam--Early works to 1800.
Religious life--Islam--Early works to 1800.