Sahih Muslim 1591 e
Hanash reported:
We were along with Fadala b. Ubaid (Allah be pleased with him) in an expedition. There fell to my and my friend's lot a necklace made of gold, silver and jewels. I decided to buy that. I asked Fadala b. 'Ubaid, whereupon he said: Separate its gold and place it in one pan (of the balance) and place your gold in the other pan, and do not receive but equal for equal, for I heard Allah's Messenger (ﷺ) as saying: He who believes in Allah and the Hereafter should not take but equal for equal.
حَدَّثَنِي أَبُو الطَّاهِرِ، أَخْبَرَنَا ابْنُ وَهْبٍ، عَنْ قُرَّةَ بْنِ عَبْدِ الرَّحْمَنِ الْمَعَافِرِيِّ، وَعَمْرِو، بْنِ الْحَارِثِ وَغَيْرِهِمَا أَنَّ عَامِرَ بْنَ يَحْيَى الْمَعَافِرِيَّ، أَخْبَرَهُمْ عَنْ حَنَشٍ، أَنَّهُ قَالَ كُنَّا مَعَ فَضَالَةَ بْنِ عُبَيْدٍ فِي غَزْوَةٍ فَطَارَتْ لِي وَلأَصْحَابِي قِلاَدَةٌ فِيهَا ذَهَبٌ وَوَرِقٌ وَجَوْهَرٌ فَأَرَدْتُ أَنْ أَشْتَرِيَهَا فَسَأَلْتُ فَضَالَةَ بْنَ عُبَيْدٍ فَقَالَ انْزِعْ ذَهَبَهَا فَاجْعَلْهُ فِي كِفَّةٍ وَاجْعَلْ ذَهَبَكَ فِي كِفَّةٍ ثُمَّ لاَ تَأْخُذَنَّ إِلاَّ مِثْلاً بِمِثْلٍ فَإِنِّي سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏
"‏ مَنْ كَانَ يُؤْمِنُ بِاللَّهِ وَالْيَوْمِ الآخِرِ فَلاَ يَأْخُذَنَّ إِلاَّ مِثْلاً بِمِثْلٍ ‏"‏ ‏.‏