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