From Sahih Bukhari (Hadith 6000):
Narrated Abu Huraira:I heard Allah's Messenger (ﷺ) saying, Allah divided Mercy into one hundred parts. He kept ninety nine parts with Him and sent down one part to the earth, and because of that, its one single part, His Creations are merciful to each other, so that even the mare lifts up its hoofs away from its baby animal, lest it should trample on it
Reference: Bukhari 6000