Musnad Ahmad 30:461

Abu Kamil narrated to us, Ibrahim ibn Sa'd narrated to us, Ibn Shihab narrated to us, from Ubayd Allah ibn Abd Allah, from Abu Hurayrah, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "There was a man who used to lend to people, and he would say to his servant: 'When you come to someone in difficulty, overlook it for him, perhaps Allah will overlook our faults.' So he met Allah, the Mighty and Majestic, and He overlooked his faults."