Sahih Muslim Book - 44, Hadith - 6330

حَدَّثَنَا أَبُو كُرَيْبٍ مُحَمَّدُ بْنُ الْعَلاَءِ ، حَدَّثَنَا يَحْيَى بْنُ آدَمَ ، حَدَّثَنَا قُطْبَةُ هُوَ ابْنُ عَبْدِ الْعَزِيزِ ، عَنِ الأَعْمَشِ ، عَنْ مَالِكِ بْنِ الْحَارِثِ ، عَنْ أَبِي الأَحْوَصِ ، قَالَ : كُنَّا فِي دَارِ أَبِي مُوسَى مَعَ نَفَرٍ مِنْ أَصْحَابِ عَبْدِ اللهِ ، وَهُمْ يَنْظُرُونَ فِي مُصْحَفٍ ، فَقَامَ عَبْدُ اللهِ ، فَقَالُ أَبُو مَسْعُودٍ : مَا أَعْلَمُ رَسُولَ اللهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ تَرَكَ بَعْدَهُ أَعْلَمَ بِمَا أَنْزَلَ اللَّهُ مِنْ هَذَا الْقَائِمِ ، فَقَالَ أَبُو مُوسَى : أَمَا لَئِنْ قُلْتَ ذَاكَ ، لَقَدْ كَانَ يَشْهَدُ إِذَا غِبْنَا ، وَيُؤْذَنُ لَهُ إِذَا حُجِبْنَا.

It was narrated that Abul-Ahwas said: "We were in the house of Abu Musa with a number of the companions of 'Abdullah, and they were looking at a Muhsaf. 'Abdullah stood up and Abu Mas'ud said: 'I do not think that the Messenger of Allah (s.a.w) has left behind anyone who is more knowledgeable of that which Allah has revealed than this one who is standing up.' Abu Musa said: 'Exactly. He was present when we were absent, and he was admitted when we were not."'