It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "The example of the companion of the Qur'an (the memorizer) is like that of a man whose camels are tied; if he takes care of them, he will keep them under control, and if he lets them go, the camels will run away."