Asrar al-Tawhid fi Maghamat al-Sheikh Abusa'id (Persian: اسرار التوحید فی مقامات ابوسعید, Arabic: اسرار التوحيد في مقامات ابو سعيد, "The Mysteries of Unification") is a book of 12th century Persian literature about the Sufi mystic Abū-Sa'īd Abul-Khayr.

Thought to be written by Muhammad ibn Monavvar, one of Abul-Khayr's grandsons, 130 years after his death, it is also considered a landmark work of Sufi literature as well as one of the most outstanding Persian prose works of the 12th century.