كتاب المساقاة
22  
The Book of Musaqah
(22)
Chapter: It is permissible to lend animals and it is recommended to pay in full, giving something better than that which ts owed
(22)
باب مَنِ اسْتَسْلَفَ شَيْئًا فَقَضَى خَيْرًا مِنْهُ وَ ‏"‏ خَيْرُكُمْ أَحْسَنُكُمْ قَضَاءً ‏"‏ ‏‏
Sahih Muslim 1601 b

Abu Huraira (Allah be pleased with him) reported:

Allah's Messenger (ﷺ) took a camel on loan, and then returned him (the lender) the camel of a more mature age and said: Good among you are those who are good in clearing off the debt.
حَدَّثَنَا أَبُو كُرَيْبٍ، حَدَّثَنَا وَكِيعٌ، عَنْ عَلِيِّ بْنِ صَالِحٍ، عَنْ سَلَمَةَ بْنِ كُهَيْلٍ، عَنْ أَبِي، سَلَمَةَ عَنْ أَبِي هُرَيْرَةَ، قَالَ اسْتَقْرَضَ رَسُولُ اللَّهِ صلى الله عليه وسلم سِنًّا فَأَعْطَى سِنًّا فَوْقَهُ وَقَالَ ‏ "‏ خِيَارُكُمْ مَحَاسِنُكُمْ قَضَاءً ‏"‏ ‏.‏
Reference : Sahih Muslim 1601b
In-book reference : Book 22, Hadith 150
USC-MSA web (English) reference : Book 10, Hadith 3899
  (deprecated numbering scheme)