السلام عليكم و رحمة الله و بركاتهThey say there is no order in the topics in the Quran and they find it difficult.
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
The Qur'an was revealed in the Arabic language according to the style and methods of expression used by the Arabs.
It is the habit of the Arabs to use different styles of speech and to move from one topic to the other when talking. However, many scholars tried to correlate between the Qur'anic verses, as well as between its Chapters.
For example, Al-Biqaa’i authored his book Nuthum Ad-Durar fi Tanaasub Al-Aayaat was-Suwar, addressing this subject.
Also, recently, the idea of the interpreting the Qur'an based on its topics has spread, in which the author analysis and studies a particular topic that is mentioned in the Qur'an.
Sayyid Qutb in his book entitled Fi Thilaal Al-Qur’aan, clarified and attached great importance to the unity of the topics within the Soorah. He singled out an introduction whereby he speaks about the content of the Surah and tries to find a comprehensive theme that encompasses all its topics.
All the aforementioned methods about Tafseer (interpretation of the meaning of the Qur'an) and the attempt of understanding it, could make it easier for the one studying the Qur'an to familiarize himself with its various topics, help him understand its objectives, and give him some understanding of the order of its verses and its Soorahs.
Understanding the correlation of the topics of the Qur'an and knowing the unity of the topic within the Soorah, facilitates its memorization. However, the most important matter that helps in memorization is the continuous repetition and revision of what has been memorized previously, because the Qur'an escapes one's mind (is forgotten) faster than camels that are released from their tying ropes, as confirmed from the Prophet in an authentic narration.
Verily, Allah facilitated the memorization of the Qur'an, so whoever endeavors to reach its objectives and benefit from its meaning and does his best in understanding and memorizing it, then Allah will help him in his effort. However, one should continuously review whatever was memorized previously as this is the best method in memorizing the Qur'an.
Allah knows best.
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