Al-Adab Al-Mufrad, Book 5, Hadith 100 (English) ⓘ

Abu Hurayra reported that the Messenger of Allah, may Allah bless him and grant him peace, said, "Allah Almighty has divided mercy into one hundred parts. He kept ninety-nine parts and sent down one part to earth. Because of that one single part, creatures are merciful to one another so that even the mare will lift its hooves away from its foal so that it does not trample on it."

حَدَّثَنَا الْحَكَمُ بْنُ نَافِعٍ، قَالَ‏:‏ أَخْبَرَنَا شُعَيْبٌ، عَنِ الزُّهْرِيِّ، قَالَ‏:‏ أَخْبَرَنَا سَعِيدُ بْنُ الْمُسَيِّبِ، أَنَّ أَبَا هُرَيْرَةَ قَالَ‏:‏ سَمِعْتُ رَسُولَ اللهِ صلى الله عليه وسلم يَقُولُ‏:‏ جَعَلَ اللَّهُ عَزَّ وَجَلَّ الرَّحْمَةَ مِئَةَ جُزْءٍ، فَأَمْسَكَ عِنْدَهُ تِسْعَةً وَتِسْعِينَ، وَأَنْزَلَ فِي الأَرْضِ جُزْءًا وَاحِدًا، فَمِنْ ذَلِكَ الْجُزْءِ يَتَرَاحَمُ الْخَلْقُ، حَتَّى تَرْفَعَ الْفَرَسُ حَافِرَهَا عَنْ وَلَدِهَا، خَشْيَةَ أَنْ تُصِيبَهُ‏.‏