Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) says: Safeguard the Qur'an, for it slips away from a person's heart just as a tied camel escapes when released. And the Messenger of Allah (peace and blessings be upon him) said: It is very bad for someone to say, "I have forgotten such-and-such verse," rather, in reality, he has been made to forget it.