(86) باب مَا يُسْتَحَبُّ مِنْ إِعْمَاقِ الْقَبْرِ
It was narrated that Hisham bin 'Amir said:
"We complained to the Messenger of Allah on the day of Uhud, saying: 'O Messneger of Allah, it is too difficult for us to dig a grave for each person.' The Messenger of Allah said: 'Dig graves and make them good and deep, and bury two or three in one grave.' They said: 'Who should we put in first, O Messenger of Allah?' He said: 'Put in first the one who knew more Qur'an."' He said: "My father was the third of three in one grave."
Reference: Sunan an-Nasa'i 2010
In-book reference: Book 21, Hadith 194
English translation: Vol. 3, Book 21, Hadith 2012