Musannaf Ibn Abi Shaybah 12009 — Two men buried in one grave

It is narrated from Sayyiduna Jabir bin Abdullah (may Allah be pleased with him) that on the day of the Battle of Uhud the bodies of two martyrs would be brought to the Prophet (peace and blessings be upon him) to be buried in a single grave, and he (peace and blessings be upon him) would ask: "Which of the two had memorized more of the Qur'an?" When one of them was pointed out, he (peace and blessings be upon him) would place him first in the lahd.