This is documented in the Sunni Hadiths (the sayings and traditions of Muhammad). Jābir ibn Abd Allah (جابِر بن عَبْد الله) narrated: "Some people drank alcoholic beverages in the morning [of the day] of the ’Uhud battle and on the same day they were killed as martyrs, and that was before wine was prohibited." ’Anas ibn Mālik (أَنَس بن مالِك) narrated that the people said: "...some people [Muslims] were killed in the Battle of ’Uhud while wine was in their stomachs.' [...] So Allah revealed: 'There is not upon those who believe and do righteousness [any] blame concerning what they have eaten [in the past] if they [now] fear Allah and believe and do righteous deeds...'" [sura 5:93]