Jabir (May Allah be pleased with him) reported: After the battle of Uhud, the Prophet (PBUH) arranged the burial of two of the martyrs in one grave. In each case he would ask, "Which one of them had learnt more Qur'an by heart?'' Whichever was thus pointed out to him was placed by him first in the Lahd. [Al-Bukhari]

Commentary:  Lahd is a type of grave in which a niche is made on the left side of it to place the corpse. The grave which is straight, a common type, is called Darih. This Hadith tells about the distinction of the Hafiz and his superiority over others. Similarly, the learned, the pious and men of outstanding virtues should have preference over others. The Hadith also indicates the permissibility to bury two or three persons in a single grave in time of need or necessity.