The Prophet ﷺ said, "If the believer knew the punishment that Allah has prepared, no one would hope for Paradise, and if the disbeliever knew the mercy that Allah has, no one would despair of Paradise. Allah created one hundred mercies. He placed one of them among His creation, by which they show mercy to one another, and with Allah remain ninety-nine mercies."
حدثنا عبد الرحمن قال حدثنا زهير عن العلاء عن أبيه
عن النبي ﷺ قال لو يعلم المؤمن ما عند الله عز وجل من العقوبة ما طمع بالجنة أحد ولو يعلم الكافر ما عند الله من الرحمة ما قنط من الجنة أحد خلق الله مائة رحمة فوضع واحدة بين خلقه يتراحمون بها وعند الله تسعة وتسعون رحمة
Its isnad is sahih. Bukhari related it, 1338, in Riqaq, Hope with Fear, and Muslim in Tawbah, 2109/4, no. 2755, and Tirmidhi, 549/5, no. 3542, and graded it hasan, and Ibn Hibban, 625, no. 2523. This tafsir comes from the narrator and not from the Prophet, and the tafsir of Muhaqalah has already been given.