question #3 Sahih Muslim 790b, Book 6, Hadith 270 : What should a person avoid saying if they forget a verse of the Qur’an, according to Islamic teachings?

Keep refreshing your knowledge of the sacred books (or always renew your knowledge of these sacred books) and sometimes he would mention the Qur’an for it is more apt to escape from men’s minds than animals which are hobbled, and the Messenger of Allah (ﷺ) said: None of you should say: I forgot such and such a verse, but he has been made to forget.