The Messenger of Allah ﷺ said, "The Throne of the Most Merciful shook at the death of Saad bin Muaz."
حدثنا علي بن محمد حدثنا أبو معاوية عن الأعمش عن أبي سفيان
قال رسول الله ﷺ اهتز عرش الرحمن عز وجل لموت سعد بن معاذ
Bukhari narrated it in "Virtues of the Ansar," chapter on the virtues of Saad bin Muaz , hadith no. 3803, and Muslim in "Virtues of the Companions," chapter on the virtues of Saad bin Muaz
, hadith no. 2466, from the hadith of Amash, with this wording.