Narrated Ibn 'Abbas:
"They (the Companions) said: 'O Messenger of Allah, how do you hold those who died while they were drinking Khamr - considering that the prohibition of intoxicants is now revealed?' So, (the following) Ayah was revealed: "Those who believe and do righteous good deeds, there is no sin on them for what they ate (in the past), if they fear Allah and believe and do righteous good deeds."
English reference: Vol. 5, Book 44, Hadith 3052
Arabic reference: Book 47, Hadith 3329