Abu Wa'il (may Allah have mercy on him) narrated that a person came to Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) and said, "I recited the Surahs of Mufassal in one rak'ah at night." He (Ibn Mas'ud) said, "Did you recite them quickly like poetry is recited? I know those similar Surahs which the Prophet (peace and blessings of Allah be upon him) used to recite together. He mentioned twenty Surahs of Mufassal, two Surahs in each rak'ah."
Hadith Referenceاللؤلؤ والمرجان / كتاب صلاة المسافرين وقصرها / 470
Hadith Gradingمحدثین:«صحیح»
Hadith Takhrij«صحیح، أخرجه البخاري في: 10 كتاب الأذان: 106 باب الجمع بين السورتين في الركعة»