Sahih Muslim Book - 6, Hadith - 1909

وَحَدَّثَنَا أَبُو كُرَيْبٍ حَدَّثَنَا أَبُو مُعَاوِيَةَ عَنِ الأَعْمَشِ عَنْ أَبِى وَائِلٍ قَالَ جَاءَ رَجُلٌ إِلَى عَبْدِ اللَّهِ يُقَالُ لَهُ نَهِيكُ بْنُ سِنَانٍ. بِمِثْلِ حَدِيثِ وَكِيعٍ غَيْرَ أَنَّهُ قَالَ فَجَاءَ عَلْقَمَةُ لِيَدْخُلَ عَلَيْهِ فَقُلْنَا لَهُ سَلْهُ عَنِ النَّظَائِرِ الَّتِى كَانَ رَسُولُ اللَّهِ -صلى الله عليه وسلم- يَقْرَأُ بِهَا فِى رَكْعَةٍ فَدَخَلَ عَلَيْهِ فَسَأَلَهُ ثُمَّ خَرَجَ عَلَيْنَا فَقَالَ عِشْرُونَ سُورَةً مِنَ الْمُفَصَّلِ فِى تَأْلِيفِ عَبْدِ اللَّهِ.

It was narrated that Abu Wa'il said: "A man called Nahik bin Sinan came to 'Abdullah...'' A Hadith similar to that of Waki' (no. 1908), except that he said: '" Alqamah came to enter upon him, and we said to him: 'Ask him about the pairs of Surahs that the Messenger of Allah (s.a.w) used to recite in each Rak'ah.' He entered upon him and asked him, then he came out to us and said: 'Twenty Surahs in ten Rak'ah of Al-Mufassal.'"