Al Salamu 'Alaykum.
Narrated Jabir: I heard the Prophet (saw) saying, “The Throne (of Allah) shook at the death of Sa'ad ibn Mu'adh.” Through another group of narrators, Jabir added, “I heard the Prophet (saw) saying, ‘The Throne of the Most Beneficent shook because of the death of Sa'ad ibn Mu'adh.”
Narrated Ibn 'Umar that the Messenger of Allah (saw) said: “This (i.e. Sa'ad ibn Mu'adh) is the one at whose death the Throne shook, the gates of heaven were opened for him and seventy thousand angels attended his funeral. It (his grave) squeezed him once then released him.”