"I heard Abu Wa'il say: "A man said in the presence of Abdullah: 'I recited Al-Mufassal in one rak'ah.' He said: 'That is like reciting poetry. I know the similar surahs that the Messenger of Allah ﷺ used to recite together.' And he mentioned twenty surahs from Al-Mufassal, two by two in each rak'ah."
رَجُلٌ عِنْدَ عَبْدِ اللَّهِ قَرَأْتُ الْمُفَصَّلَ فِي رَكْعَةٍ قَالَ هَذًّا كَهَذِّ الشِّعْرِ لَقَدْ عَرَفْتُ النَّظَائِرَ الَّتِي كَانَ رَسُولُ اللَّهِ ﷺ يَقْرُنُ بَيْنَهُنَّ فَذَكَرَ عِشْرِينَ سُورَةً مِنَ الْمُفَصَّلِ سُورَتَيْنِ سُورَتَيْنِ فِي رَكْعَةٍ