Man Lā Yaḥḍuruh al-Faqīh
Hadith 3964025 - وَ رَوَى اِبْنُ مُسْكَانَ عَنِ اَلْحَلَبِيِّ قَالَ : سَأَلْتُ أَبَا عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ عَنِ اَلرَّجُلِ يَسْتَقْرِضُ اَلدَّرَاهِمَ اَلْبِيضَ عَدَداً وَ يَقْضِي سُوداً وَزْناً وَ قَدْ عَرَفَ أَنَّهَا أَثْقَلُ مِمَّا أَخَذَ وَ تَطِيبُ بِهَا نَفْسُهُ أَنْ يَجْعَلَ لَهُ فَضْلَهَا قَالَ "لاَ بَأْسَ بِهِ إِذَا لَمْ يَكُنْ فِيهِ شَرْطٌ وَ لَوْ وَهَبَهَا لَهُ كُلَّهَا صَلَحَ".
Hadith.4025 - Ibn Muskan narrated from al-Halabi, who said: I asked Abu Abdullah (as) about a man who borrows a specified amount of white dirhams and repays them with black dirhams by weight, knowing that they are heavier than what he borrowed, and he willingly gives the extra weight.
Imam (as) said: "There is no harm in it as long as it is not a condition. Even if he gifted him all of it, it would be permissible."