What is the ruling on writing or explaining the meanings of words in the pages of the Mushaf?

Scholars have differed on the ruling of writing exegesis (tafsir) or meanings in the margins of the Mus'haf (copy of the Qur'an), holding two opinions: permissibility and impermissibility.

- The opinion of permissibility: Proponents of this view cited the actions of some Companions, such as 'Aishah and Ubayy ibn Ka'b, who permitted the inclusion of non-Qur'anic material with it, in addition to the statements of some imams like Malik, the Hanafis, and the Shafi'is. They pointed out that the reason for dislike (which was the fear of confusing Allah's words with other texts) has vanished in this era due to advancements in printing and clear differentiation, and because it facilitates knowledge.

- The opinion of impermissibility (or dislike): Proponents of this view relied on reports from the Salaf (pious predecessors) like 'Ata', 'Abdullah ibn Mas'ud, and Ibrahim al-Nakha'i, who disliked writing anything in the Mus'haf out of fear of mixing the Qur'an with other texts, as well as some statements of later Shafi'i and Hanafi scholars and the Permanent Committee (for Islamic Research and Fatwas) which advised keeping the Mus'haf pure.

The more evident opinion is that of permissibility, due to the absence of sound evidence prohibiting it, the actions of some Companions, and because the reason for dislike has vanished with the development of Mus'haf printing and the presence of an educational need that facilitates knowledge for many people.