علم يبحث فيه عن القرآن المجيد من حيث دلالته على مراد الله تعالى بقدر الطاقة البشرية
Tafsir is the discipline that examines the Glorious Qur'an with regard to how it indicates what Allah intends, to the extent of human capacity.
The subject is the Qur'an; the specific inquiry concerns its indication of divine intent; and the qualification is the limit of human ability. Consequently, not every activity related to the Qur'an constitutes the central inquiry of tafsir.
Writing a muṣḥaf and performing recitation are important activities, but a commentator's principal task is to establish the meaning and guidance conveyed by a passage.