Allah ta’ala says in surah Fussilat ayah three,
A Book, whereof the verses are explained in detail; a Qur’an in Arabic, for people who understand. (41:3)
Usually Surahs are named after an ism/noun, but this surah is named after a verb (fussilat is a fi’l/verb). This verb is a description of the Qur’an that appears in ayat 3 and 44 in this surah.
Fussilat means one that openly explains and is set out in detail. It comes from the root ‘fasl’ which means to set something apart in order to clarify. From this word comes tafseel, which means to set something out in detail, to explain it in sequence. The word mufassal is also used for something that is tailored and meets certain requirements.
How is the Qur’an Fussilat?
1- Its ayaat are explained clearly and in detail. It is explained through the mention of ahkam/rulings, stories, and parables in order to make the message very clear.
2- The ayaat have been stated in order and in a certain sequence. One surah leads to another in a certain sequence so that the Qur’an can be understood and applied by the person.
3- Each ayah is separate. The ayaat of the Qur’an are not just words and lines, they are distinguishable ayaat.
4- Separate in revelation; one part was revealed after another part.
Listen to a beautiful recitation of surah Fussilat here.