That the Prophet ﷺ said: "Fulfill the trust for the one who entrusted you, and do not cheat the one who cheated you." (Using translation from Tirmidhī 1264)  

عَنِ النَّبِيِّ ﷺ قَالَ «أَدِّ الْأَمَانَةَ إِلَى مَنِ ائْتَمَنَكَ وَلَا تَخُنْ مَنْ خَانَكَ»