Abu Dawud Book 14, Hadith Number 3209.
Chapter : Not known.
Narated By Hisham ibn Amir : The Ansar came to the Apostle of Allah (PBUH) on the day of Uhud and said: We have been afflicted with wound and fatigue. What do you command us?
He said: Dig graves, make them wide, bury two or three in a single grave.
He was asked: Which of them should be put first?
He replied: The one who knew the Qur’an most.
He (Hisham) said: My father Amir died on the day and was buried with two or one.