Narrated Anas [May Allah be pleased with him]:
"While the Messenger of Allah (ﷺ) was returning from Al-Hudaibiyyah it was revealed to him, 'That Allah may forgive you your sins of the past and the future (48:2).' So the Prophet (ﷺ) said: 'An Ayah has been revealed to me which is dearer to me than whatever is upon the earth.' Then the Prophet (ﷺ) recited it for them and they said: 'Congratulations O Messenger of Allah! Allah has explained what He will do with you, but what will He do with us?' So (the following) was revealed: 'That He may admit the believing men and the believing women into Gardens under which rivers flow' up to (His Saying) 'a supreme success (48:5).'"
English reference: Vol. 5, Book 44, Hadith 3263
Arabic reference: Book 47, Hadith 3573