Abul-Qasim al-Qushayri (986–1072 CE) was a towering Persian scholar, theologian, and mystic who played a pivotal role in reconciling orthodox Sunni Islam with Sufism. Born in the Khorasan region, he was a master of multiple disciplines, including Shafi'i jurisprudence, Ash'ari theology, and Hadith. He is most renowned for his seminal work, al-Risala al-Qushayriyya (The Qushayri Epistle), which defined the path of spiritual excellence (ihsan) by grounding mystical practices in the Quran and Sunnah, effectively defending Sufism against charges of heresy. Beyond his spiritual leadership, al-Qushayri was a prolific author whose works, such as his subtle Quranic commentary Lata'if al-Isharat, continue to be essential reading for students of Islamic spirituality and law.