What is the ruling on leaving gaps in verses to test the memorization of the Qur'an by the deaf and mute?

There is no harm in testing and revising the memorization of the Qur’an in this manner, especially since it is easy and beneficial for ascertaining the extent of one's memorization and proficiency. The permissibility of this is indicated by the fact that the reciters (Qurra’) used to pause their students at certain points to test them.