Al-Sijistani refers to people from the historic Sijistan region in present-day Sistan, the border region of eastern Iran and southwestern Afghanistan. Prominent people who have been called Al-Sijistani include: Abu Da'ud Sulayman ibn Ash`ath al-Azadi al-Sijistani (817-888 CE), ("Abu Dawūd"), collector of hadith Abu Yaqub Sijistani (died c. 971 CE), Neoplatonist and Ismaili missionary Abu Sulayman Muhammad al-Sijistani (c. 932 - c. 1000 CE), Islamic philosopher, flourished in Baghdad Al-Sijzi (c. 945 - c. 1020 CE), mathematician and astronomer Masʽud ibn Muhammad Sijzi, 14th-century Persian physician Surnames Nisbas People from Sistan Ethonymic surnames Arabic-language surnames Persian-language surnames