Is it permissible to add annotations and write benefits on a book of tafsir?

The questioner:
May Allah reward you, Your Eminence, father. The questioner asks: Is it permissible to write some benefits and explanation on a book of tafsir?

The Shaykh:
No, it is not permissible. The mushaf is intended to be the mushaf, and not the tafsir?

The questioner:
The tafsir.

The Shaykh:
Tafsir is fine. A tafsir book is not the Qur'an, so it is permissible for you to annotate it and write in its margins. As for the Qur'an and the mushaf, no, it is not permissible. Yes.