Sahih Muslim 1588 c
Abu Huraira (Allah be pleased with him) reported Allah's Mess-., nger (ﷺ) as saying:
Gold is to be paid for by gold with equal weight, like for like, and silver is to be paid for by silver with equal weight, like for like. He who made an addition to it or demanded an addition dealt in usury.
حَدَّثَنَا أَبُو كُرَيْبٍ، وَوَاصِلُ بْنُ عَبْدِ الأَعْلَى، قَالاَ حَدَّثَنَا ابْنُ فُضَيْلٍ، عَنْ أَبِيهِ، عَنِ ابْنِ أَبِي نُعْمٍ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏
"‏ الذَّهَبُ بِالذَّهَبِ وَزْنًا بِوَزْنٍ مِثْلاً بِمِثْلٍ وَالْفِضَّةُ بِالْفِضَّةِ وَزْنًا بِوَزْنٍ مِثْلاً بِمِثْلٍ فَمَنْ زَادَ أَوِ اسْتَزَادَ فَهُوَ رِبًا‏"‏ ‏.‏