It was narrated that Ibn 'Abbas said:

When the prohibition on khamr (alcohol) was revealed, they said: O Messenger of Allah, what about our brothers who died, and they used to drink it? Then the verse "Those who believe and do righteous good deeds, there is no sin on them for what they ate (in the past)...” [al-Ma’idah 5:93 - to the end of the verse] was revealed.