Sahih Muslim 2492 a
Al-A'raj reported that he heard Abu Huraira as saying:
You are under the impression that Abu Huraira transmits so many ahadith from Allah's Messenger (may peace up upon him) ; (bear in mind) Allah is the great Reckoner. I was a poor man and I served Allah's Messenger (ﷺ) being satisfied with bare subsistence, whereas the immigrants remained busy with transactions in the bazar; while the Ansar had been engaged in looking after their properties. (He further reported) that Allah's Messenger (ﷺ) said: He who spreads the cloth would not forget anything that he would hear from me. I spread my cloth until he narrated something. I then pressed it against my (chest), so I never forgot anything that I heard from him.
حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، وَأَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ وَزُهَيْرُ بْنُ حَرْبٍ جَمِيعًا عَنْ سُفْيَانَ،
 قَالَ زُهَيْرٌ حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنِ الزُّهْرِيِّ، عَنِ الأَعْرَجِ، قَالَ سَمِعْتُ أَبَا هُرَيْرَةَ، يَقُولُ
 إِنَّكُمْ تَزْعُمُونَ أَنَّ أَبَا هُرَيْرَةَ، يُكْثِرُ الْحَدِيثَ عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم وَاللَّهُ الْمَوْعِدُ
 كُنْتُ رَجُلاً مِسْكِينًا أَخْدُمُ رَسُولَ اللَّهِ صلى الله عليه وسلم عَلَى مِلْءِ بَطْنِي وَكَانَ الْمُهَاجِرُونَ
 يَشْغَلُهُمُ الصَّفْقُ بِالأَسْوَاقِ وَكَانَتِ الأَنْصَارُ يَشْغَلُهُمُ الْقِيَامُ عَلَى أَمْوَالِهِمْ فَقَالَ رَسُولُ اللَّهِ
 صلى الله عليه وسلم ‏
"‏ مَنْ يَبْسُطُ ثَوْبَهُ فَلَنْ يَنْسَى شَيْئًا سَمِعَهُ مِنِّي ‏"‏ ‏.‏ فَبَسَطْتُ ثَوْبِي
 حَتَّى قَضَى حَدِيثَهُ ثُمَّ ضَمَمْتُهُ إِلَىَّ فَمَا نَسِيتُ شَيْئًا سَمِعْتُهُ مِنْهُ ‏.‏