Abu Hurairah reported,

I heard the Messenger of Allah ﷺ say, "When Allah created mercy, He created it as one hundred parts. He kept ninety-nine parts with Himself and sent down a single part among all of His creation. If the disbeliever knew the full extent of the mercy that Allah has, he would not despair of Paradise, and if the believer knew the full extent of the punishment that Allah has, he would not feel safe from the Fire."

Azami 11402

Sahih

عن أبي هريرة قال

سمعت رسول الله ﷺ يقول: إن الله خلق الرحمة يوم خلقها مائة رحمة، فأمسك عنده تسعا وتسعين رحمة، وأرسل في خلقه كلهم رحمة واحدة، فلو يعلم الكافر بكل الذي عند الله من الرحمة لم ييئس من الجنة، ولو يعلم المؤمن بكل الذي عند الله من العذاب لم يأمن من النار.

الأعظمي 11402صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Repentance and seeking forgiveness
Chapter
Comprehensive and general supplications
Section
Vastness of the mercy of Allah and that it precedes His wrath
Numbering
Jami al-Kamil 11402 (2nd edition)
Azami 11402