The one memorizing the Qur'aan should not depend upon memorizing by himself without the need for a teacher. He/She must recite what they have memorized to another person who has perfected the memorization of the Qur'aan, or to someone who listens to their recitation while looking at the Qur'aan, especially when that person is one who has perfected the tajweed of the Qur'aan.
This is important so that the teacher (the Haafidh upon whom the memorized portion is being recited) can correct the mistakes, if there is any, or in case the memorizer forgets while reciting and perhaps repeats unconsciously without paying attention to what they are reciting. Many times when a memorizer of the Qur'aan makes mistakes in their memorization and if they do not recite unto someone else, they will not know they memorized it wrong. He/She may not even notice the mistake even when they look in the mushaf as they memorize or review. This happens because our recitation from memory often precedes the attention we pay to the pages of the mushaf when looking in it as we recite. So, someone may sincerely intend to identify their error in hifdh but may be unable to identify it on their own.
Reciting to another person is a fundamental pillar of memorizing and perfecting the memorization. It would be unfortunate if we think we can do it alone, put in all the effort and time, only to realize that we made mistakes in our memorization. Not only will it ruin our morale, it will be very difficult to correct such mistakes if we have stored it in our memory. Reciting to a teacher, someone who knows the Qur'aan by heart and has perfected its tajweed, is a means to ensure we do not fall into this error. It is also a means to ensure we always pay attention to what we memorize and recite.
The source and main material used in preparing the content of this blog is the book, Ways of teaching the noble Qur'aan and memorizing it by Abu Abdrahman, Jamal ibn Ibrahim AlQirsh (طرائق تدريس القرآن الكريم وحفظه).