That the Prophet (ﷺ) said: "Fulfill the trust for the one who entrusted you, and do not cheat the one who cheated you." [Abu 'Eisa said:] This Hadith is Hasan Gharib. Some of the people of knowledge followed this Hadith, they said that when something belonging to a man is with another and he leaves (with it), then he has something that belongs to him, he may not withhold from him an equivalent to what the other took of his. Some of the people of knowledge among the Tabi'in allowed that. This is the view of Sufyan Ath-Thawri, he said: "If one man has some Dirham that belong to another, and the second has some Dinar belonging to the first, he may not withhold any in place of his Dirham, unless it so happens that he has some Dirham of his, then in that case he can withhold some of his Dirham equal to what he is owed by the first."
حَدَّثَنَا أَبُو كُرَيْبٍ، حَدَّثَنَا طَلْقُ بْنُ غَنَّامٍ، عَنْ شَرِيكٍ، وَقَيْسٍ، عَنْ أَبِي حَصِينٍ، عَنْ أَبِي صَالِحٍ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ النَّبِيُّ صلى الله عليه وسلم أَدِّ الأَمَانَةَ إِلَى مَنِ ائْتَمَنَكَ وَلاَ تَخُنْ مَنْ خَانَكَ . قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ غَرِيبٌ . وَقَدْ ذَهَبَ بَعْضُ أَهْلِ الْعِلْمِ إِلَى هَذَا الْحَدِيثِ وَقَالُوا إِذَا كَانَ لِلرَّجُلِ عَلَى آخَرَ شَيْءٌ فَذَهَبَ بِهِ فَوَقَعَ لَهُ عِنْدَهُ شَيْءٌ فَلَيْسَ لَهُ أَنْ يَحْبِسَ عَنْهُ بِقَدْرِ مَا ذَهَبَ لَهُ عَلَيْهِ . وَرَخَّصَ فِيهِ بَعْضُ أَهْلِ الْعِلْمِ مِنَ التَّابِعِينَ . وَهُوَ قَوْلُ الثَّوْرِيِّ وَقَالَ إِنْ كَانَ لَهُ عَلَيْهِ دَرَاهِمُ فَوَقَعَ لَهُ عِنْدَهُ دَنَانِيرُ فَلَيْسَ لَهُ أَنْ يَحْبِسَ بِمَكَانِ دَرَاهِمِهِ إِلاَّ أَنْ يَقَعَ عِنْدَهُ لَهُ دَرَاهِمُ فَلَهُ حِينَئِذٍ أَنْ يَحْبِسَ مِنْ دَرَاهِمِهِ بِقَدْرِ مَا لَهُ عَلَيْهِ .
Tirmizi
The Book on Business • Hadith 1273