Sunan an-Nasa'i 4617
It was narrated from Abu Rafi that the Messenger of Allah borrowed a young camel from a man, and then he came to get his camel back. He said to a man:
"Go and buy a young camel for him." He came and said: "I could only get a Raba camel of good quality." He said: "Give it to him, for the best of the Muslims is the one who is best in repaying."
أَخْبَرَنَا عَمْرُو بْنُ عَلِيٍّ، قَالَ حَدَّثَنَا عَبْدُ الرَّحْمَنِ، قَالَ حَدَّثَنَا مَالِكٌ، عَنْ زَيْدِ بْنِ أَسْلَمَ، عَنْ عَطَاءِ بْنِ يَسَارٍ، عَنْ أَبِي رَافِعٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم اسْتَسْلَفَ مِنْ رَجُلٍ بَكْرًا فَأَتَاهُ يَتَقَاضَاهُ بَكْرَهُ فَقَالَ لِرَجُلٍ ‏"‏ انْطَلِقْ فَابْتَعْ لَهُ بَكْرًا ‏"‏ ‏.‏ فَأَتَاهُ فَقَالَ مَا أَصَبْتُ إِلاَّ بَكْرًا رَبَاعِيًّا خِيَارًا ‏.‏ فَقَالَ ‏"‏ أَعْطِهِ فَإِنَّ خَيْرَ الْمُسْلِمِينَ أَحْسَنُهُمْ قَضَاءً ‏"‏ ‏.‏