Zirr says that once a man asked Sayyiduna Ibn Mas'ud (may Allah be pleased with him): How do you recite this verse: «مِنْ مَاءٌ غَيْرُ يَاسِنٍ» or «آسِنٍ» — with ya or with alif? Sayyiduna Ibn Mas'ud (may Allah be pleased with him) replied: Have you memorized the entire Qur'an except for this verse? He said: (You can estimate from this) I recite the Mufassalat in one rak'ah. Sayyiduna Ibn Mas'ud (may Allah be pleased with him) said: Like poetry? I also know examples where the Prophet (peace and blessings be upon him) recited two surahs in one rak'ah, both of which were from the Mufassalat. It should be noted that in the Mushaf of Sayyiduna Ibn Mas'ud (may Allah be pleased with him), the Mufassalat began from Surah Rahman.