I heard Messenger of Allah ﷺ as saying: Allah created mercy in one hundred parts and He retained with Him ninety-nine parts, and He has sent down upon the earth one part, and it is because of this one part that there is mutual love among the creation so much so that the animal lifts up its hoof from its young one, fearing that it might harm it. (Using translation from Muslim 2752a)  

سَمِعْتُ النَّبِيَّ ﷺ يَقُولُ «جَعَلَ اللَّهُ الرَّحْمَةَ مِائَةَ جُزْءٍ فَأَمْسَكَ عِنْدَهُ تِسْعَةً وَتِسْعِينَ وَأَنْزَلَ فِي الْأَرْضِ جُزْءًا وَاحِدًا فَمِنْ ذَلِكَ الْجُزْءِ يَتَرَاحَمُ الْخَلْقُ حَتَّى تَرْفَعَ الْفَرَسُ حَافِرَهَا عَنْ وَلَدِهَا خَشْيَةَ أَنْ تُصِيبَهُ»