‘Ali ibn ‘Usman Hujviri

Abu al-Hasan Ali ibn Uthman al-Jullabi al-Hujwiri, known reverentially as Data Sahib, was an Islamic scholar and mystic who authored Kashf al-Mahjub, the earliest treatise on Sufism in the Persian language. Born in the Ghaznavid Empire, al-Hujwiri is believed to have contributed "significantly" to the spread of Islam in South Asia through his preaching.