"I heard Abu Saeed Al-Khudri say: 'A Dirham for a Dirham and a Dinar for a Dinar.' So I said: 'I heard Ibn 'Abbas say something other than that.' He said: 'But I met Ibn 'Abbas and said: "Tell me about what you say concerning exchange is it something that you heard from the Messenger of Allah ﷺ or something that You found in the Book of Allah?" He said: "I did not find it in the Book of Allah, and I did not hear it from the Messenger of Allah; rather Usamah bin Zaid told me that the Messenger of Allah ﷺ said: "Usury is only in credit."[1]  

سَمِعْتُ أَبَا سَعِيدٍ الْخُدْرِيَّ يَقُولُ الدِّرْهَمُ بِالدِّرْهَمِ وَالدِّينَارُ بِالدِّينَارِ فَقُلْتُ إِنِّي سَمِعْتُ ابْنَ عَبَّاسٍ يَقُولُ غَيْرَ ذَلِكَ قَالَ أَمَا إِنِّي لَقِيتُ ابْنَ عَبَّاسٍ فَقُلْتُ أَخْبِرْنِي عَنْ هَذَا الَّذِي تَقُولُ فِي الصَّرْفِ أَشَىْءٌ سَمِعْتَهُ مِنْ رَسُولِ اللَّهِ ﷺ أَمْ شَىْءٌ وَجَدْتَهُ فِي كِتَابِ اللَّهِ فَقَالَ مَا وَجَدْتُهُ فِي كِتَابِ اللَّهِ وَلاَ سَمِعْتُهُ مِنْ رَسُولِ اللَّهِ وَلَكِنْ أَخْبَرَنِي أُسَامَةُ بْنُ زَيْدٍ أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِنَّمَا الرِّبَا فِي النَّسِيئَةِ  

"I heard him meaning Ibn 'Abbas allowing exchange (of Dirhams for Dirham etc., if extra was given) and that was narrated from him. Then I heard that he has taken back this opinion. I met him in Makkah and said: 'I heard that you had taken back (your opinion).' He said: 'Yes. That was just my own opinion, but Abu Sa'eed narrated from the Messenger of Allah ﷺ that he forbade exchange (of like items if extra is given)."'  

عَنْ ذَلِكَ فَلَقِيتُهُ بِمَكَّةَ فَقُلْتُ إِنَّهُ بَلَغَنِي أَنَّكَ رَجَعْتَ قَالَ نَعَمْ إِنَّمَا كَانَ ذَلِكَ رَأْيًا مِنِّي وَهَذَا أَبُو سَعِيدٍ يُحَدِّثُ عَنْ رَسُولِ اللَّهِ ﷺ أَنَّهُ نَهَى عَنِ الصَّرْفِ