Sahih Muslim 1601
Sahih Muslim · Book 22: The Book of Musaqah · It is permissible to lend animals and it is recommended to pay in full, giving something better than that which ts owed
Abu Huraira (Allah be pleased with him) reported:
حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ نُمَيْرٍ ، حَدَّثَنَا أَبِي ، حَدَّثَنَا سُفْيَانُ ، عَنْ سَلَمَةَ بْنِ كُهَيْلٍ ، عَنْ أَبِي سَلَمَةَ ، عَنْ أَبِي هُرَيْرَةَ ، قَالَ جَاءَ رَجُلٌ يَتَقَاضَى رَسُولَ اللَّهِ صلى الله عليه وسلم بَعِيرًا فَقَالَ " أَعْطُوهُ سِنًّا فَوْقَ سِنِّهِ - وَقَالَ - خَيْرُكُمْ أَحْسَنُكُمْ قَضَاءً " .
There came a person demanding a camel from Allah's Messenger (ﷺ). He (the Holy Prophet) said: Give him (the camel) of that age or of more mature age, and said: Best among you is one who is best in clearing off the debt.