بُلُوغُ الْمَرَامِ
Bulugh al-Maram 890
Business Transactions
وَعَنْ أَبِي هُرَيْرَةَ - رضى الله عنه - قَالَ: قَالَ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -{ أَدِّ اَلْأَمَانَةَ إِلَى مَنْ اِئْتَمَنَكَ, وَلَا تَخُنْ مَنْ خَانَكَ } رَوَاهُ أَبُو دَاوُدَ, وَاَلتِّرْمِذِيُّ وَحَسَّنَهُ, وَصَحَّحَهُ اَلْحَاكِمُ, وَاسْتَنْكَرَهُ أَبُو حَاتِمٍ اَلرَّازِيُّ [1] .
Narrated Abu Hurairah (RA): Allah's Messenger (ﷺ) said: "Give back what has been entrusted (to you) to him who has entrusted you, and do not violate the trust of him who violates your trust." [Reported by at-Tirmidhi and Abu Dawud; at-Tirmidhi graded it Hasan (good) and al-Hakim graded it Sahih (authentic). Abu Hatim ar-Razi considered it Munkar (rejected)].
Sunnah.com reference: Book 7, Hadith 134