Sahih Muslim 1588b
Abu Huraira (Allah be pleased with him) reported Messenger of Allah ﷺ as saying: Dates are to be paid for by dates, wheat by wheat, barley by barley, salt by salt, like for like, payment being made on the spot. He who made an addition or demanded an addition, in fact, dealt in usury except in case where their classes differ. This hadith has been narrated on the authority of Fudail b. Ghazwan with the same chain of transmitters, but he made no mention of (payment being) made on the spot.
حَدَّثَنَا أَبُو كُرَيْبٍ، مُحَمَّدُ بْنُ الْعَلاَءِ وَوَاصِلُ بْنُ عَبْدِ الأَعْلَى قَالاَ حَدَّثَنَا ابْنُ فُضَيْلٍ، عَنْ أَبِيهِ، عَنْ أَبِي زُرْعَةَ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ ﷺ " التَّمْرُ بِالتَّمْرِ وَالْحِنْطَةُ بِالْحِنْطَةِ وَالشَّعِيرُ بِالشَّعِيرِ وَالْمِلْحُ بِالْمِلْحِ مِثْلاً بِمِثْلٍ يَدًا بِيَدٍ فَمَنْ زَادَ أَوِ اسْتَزَادَ فَقَدْ أَرْبَى إِلاَّ مَا اخْتَلَفَتْ أَلْوَانُهُ " .