Sunan an-Nasa'i, Book 44, Hadith 171 (In-Book) ⓘ
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.'''
أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ أَنْبَأَنَا عَبْدُ الرَّحْمَنِ بْنُ مَهْدِيٍّ، قَالَ حَدَّثَنَا مُعَاوِيَةُ بْنُ صَالِحٍ، قَالَ سَمِعْتُ سَعِيدَ بْنَ هَانِئٍ، يَقُولُ سَمِعْتُ عِرْبَاضَ بْنَ سَارِيَةَ، يَقُولُ بِعْتُ مِنْ رَسُولِ اللَّهِ صلى الله عليه وسلم بَكْرًا فَأَتَيْتُهُ أَتَقَاضَاهُ فَقَالَ " أَجَلْ لاَ أَقْضِيكَهَا إِلاَّ نَجِيبَةً " . فَقَضَانِي فَأَحْسَنَ قَضَائِي وَجَاءَهُ أَعْرَابِيٌّ يَتَقَاضَاهُ سِنَّهُ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " أَعْطُوهُ سِنًّا " . فَأَعْطَوْهُ يَوْمَئِذٍ جَمَلاً فَقَالَ هَذَا خَيْرٌ مِنْ سِنِّي . فَقَالَ " خَيْرُكُمْ خَيْرُكُمْ قَضَاءً " .
also referenced under: Hadith 4619 (Reference) & Volume 5, Book 44, Hadith 4623 (DarusSalam)