On the authority of Abu Hurayrah (may Allah be pleased with him), who said that the Messenger of Allah (ﷺ) said: When Allah decreed the Creation He pledged Himself by writing in His book which is laid down with Him: My mercy prevails over my wrath. It was related by Muslim (also by al-Bukhari, an-Nasa'i and Ibn Majah)
Book 1 · Hadith 1