´Irbad bin Saryah said:` "I lent a young camel to the Messenger of Allah, and I came to ask him to repay me. He said: 'Yes, I will only repay you with a superior she-camel.' so he repaid me and repaid me well. Then a Bedouin came to him to ask to repay him a camel of a certain age, and the Messenger of Allah said: 'Give him a camel of certain age.' On that day they gave him a mature camel and he said: 'This is better than my camel.' He (The Prophet) Said:' The best of you is the one who is best in repaying.'''
Hadith Referenceسنن نسائي / كتاب البيوع / 4623
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:صحيح
Hadith Takhrij«سنن ابن ماجہ/التجارات 62 (2286)، (تحفة الأشراف: 9887)، مسند احمد (4/128) (صحیح)»
“Bakhti” are a good breed of camels. The purpose was that I will give you a she-camel better and superior than your camel. Even if a she-camel is equal to a male camel in terms of quality, she is still considered valuable.
Source: Sunan Nasa'i: Translation and Benefits by Shaykh Hafiz Muhammad Amin Hafizullah, Page: 4623