Sunan an-Nasa'i, Volume 5, Book 44, Hadith 4687 (DarusSalam) ⓘ

it was narrated from Isla'il bin Ibrahim bin 'Abdullah bin Abi Rabi'ah, from his father, that his grandfather said: "The Prophet borrowed forty thousand from me, then some wealth came to him, and he paid me back and said: 'May Allah bless your family and your wealth for you: the reward for lending is praise and repayment."

حَدَّثَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا عَبْدُ الرَّحْمَنِ، عَنْ سُفْيَانَ، عَنْ إِسْمَاعِيلَ بْنِ إِبْرَاهِيمَ بْنِ عَبْدِ اللَّهِ بْنِ أَبِي رَبِيعَةَ، عَنْ أَبِيهِ، عَنْ جَدِّهِ، قَالَ اسْتَقْرَضَ مِنِّي النَّبِيُّ صلى الله عليه وسلم أَرْبَعِينَ أَلْفًا فَجَاءَهُ مَالٌ فَدَفَعَهُ إِلَىَّ وَقَالَ ‏ "‏ بَارَكَ اللَّهُ لَكَ فِي أَهْلِكَ وَمَالِكَ إِنَّمَا جَزَاءُ السَّلَفِ الْحَمْدُ وَالأَدَاءُ ‏" ‏ ‏.‏