From Meezan by Ghamidi sahib:
“The Prophet (sws) has emphatically directed people to refrain from the slightest possible trace of interest while borrowing in barter as well:
الذَّهَبُ بِالذَّهَبِ وَزْنًا بِوَزْنٍ مِثْلًا بِمِثْلٍ وَالْفِضَّةُ بِالْفِضَّةِ وَزْنًا بِوَزْنٍ مِثْلًا بِمِثْلٍ فَمَنْ زَادَ أَوْ اسْتَزَادَ فَهُوَ رِبًا
If you lend gold, then take back the same type and the same amount of gold; and if you lend silver, then take back the same type and the same amount of silver; for he who gave more or desired more, then this is precisely what interest is.
الْوَرَقُ بِالذَّهَبِ رِبًا إِلَّا هَاءَ وَهَاءَ وَالْبُرُّ بِالْبُرِّ رِبًا إِلَّا هَاءَ وَهَاءَ وَالشَّعِيرُ بِالشَّعِيرِ رِبًا إِلَّا هَاءَ وَهَاءَ وَالتَّمْرُ بِالتَّمْرِ رِبًا إِلَّا هَاءَ وَهَاءَ
If you lend gold in exchange for silver, then there is a possibility of interest in this. [5] Similarly, for wheat in exchange for another type of wheat, [6] barley in exchange for another type of barley, date for another type of date. Indeed if the exchange is done on the spot, then there is no harm.
This is the correct meaning of the above quoted Ahadith. If all the Ahadith on this topic had remained intact, the scholars of our ummah would not have faltered in interpreting them. However, owing to the misinterpretation of the narrators in some chains of narration, the words هَاءَ وَهَاءَ (on the spot), or similar words in the second Hadith quoted above, were incorporated in the first one; similarly, the word الذَّهَبُ بِالذَّهَب (gold in exchange for gold) of the Hadith quoted first were put in place of الْوَرَقُ بِالذَّهَبِ (if you lend silver in exchange for gold) of the second. It is because of this intermingling of words that our jurists have erroneously derived the concept of riba al-fadl from such Ahadith, whereas the correct concept in this regard is what the following words of the Prophet (sws) say: إِنَّمَا الرِّبَا فِي النَّسِيئَةِ (ribais only in transactions of loan.
It should be borne in mind that interest pertains only to those transactions in which a commodity is borrowed for the purpose of “using it up” whereby the borrower would be burdened to recreate it in order to return it to the lender. If any additional amount is demanded over and above it, then this no doubt is injustice as affirmed both by reason and revelation. On the contrary, transactions in which the commodities and items in question are “used” rather than being “used up” relate to lease, and the money demanded by the owner on providing this service, which is termed as rent, can in no way be objected to.”
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This shows that the actual instructions were of trading in barter on spot, lending may include interest due due to different qualities of things to exchange. If both agree on this exchange they both are guilty as both are forbidden no to do that. this has nothing to do with the actual interest which is on loan.