The Messenger of Allah ﷺ said, "When Allah finished creating, He wrote in His book, which is with Him above the Throne, 'My mercy has overcome My wrath.'"
قال رسول الله ﷺ: لما قضى الله الخلق كتب في كتابه فهو عنده فوق العرش: إن رحمتي غلبت غضبي.
Bukhari related it in the Beginning of Creation (3194), and Muslim in Repentance (2751), both from the hadith of Abu Zinad, from Araj, from Abu Hurairah, who narrated it.Ibn Khuzayma said, "This report indicates that our Lord is above His Throne, where the writing that says, 'My mercy prevails over My wrath,' is kept with Him."