A Mufassir is a scholar who specialises in "Tafsir" (the exegesis or interpretation of the Quran). Becoming a Mufassir requires mastery of numerous disciplines, including classical Arabic, grammar, Hadith, history, and the "Reasons for Revelation" (Asbab al-Nuzul). Famous Mufassirun like Ibn Kathir or Al-Tabari have provided the Ummah with the intellectual keys to unlock the deeper meanings of the Divine word, ensuring that the Quran is understood in its proper context and applied correctly to new situations.