Sayyiduna Hisham bin Amir (may Allah be pleased with him) said that on the day of Uhud the people complained to the Messenger of Allah (peace and blessings be upon him) of their wounds, (saying) that digging a grave for every person was hard. He (peace and blessings be upon him) said: "Dig them deep and well, and bury two or three in one grave." They said: "O Messenger of Allah! Whom shall we lower into the lahd first?" He (peace and blessings be upon him) said: "The one among them who has the most Qur'an." So my father was buried, the third of three.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6927