Is it permissible to memorize the Qur’an and repeat a single verse during the night prayer instead of reciting from it?

Repeating a verse in prayer is legislated for reflection and humility, as the Prophet, peace and blessings be upon him, did, and as Ibn Baz decreed. As for repeating it for the purpose of memorization, it is not legislated because memorization is not among the actions of prayer, and the worshiper should be occupied with what is legislated in prayer, such as reflection and humility.