Our Shaykh, Muhammad ibn Hizaam (may Allaah preserve him) was asked the following question:
Question:
The questioner says: Ibnul Qayyim and others from the people of knowledge have mentioned that the Prophet ﷺ would mostly recite from the Mufassal Surahs during the prayer and that it's not appropriate to start from the middle of nor the end of a Surah?
Answer:
Yes, the evidences in this regard indicate that in his prayers, the Prophetﷺ would mostly recite from the Mufassal; which begins from Surah Qaaf until Surah Naas. Most of the Prophet's recitation was from this section of the Qur'an. Nonetheless, it's been reported that the prophet ﷺ recited from other sections other than the Mufassal; he used to recite Suratus Sajdah in the 1st Rak'ah of Fajr prayer on Fridays, and this Surah is not from the Mufassal.
Likewise, the Prophet ﷺ is reported to have read Suratul A'raaf as well as Suratul Mu'minoon, and these also are not from the Mufassal. So one can recite Surahs from here and there, but there's no harm if a person wishes to read mostly from the Mufassal in his prayer. There is no harm, because Allaah -The Most High- said: