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 bearer of the Qur'an is like the owner of a tied camel; if he keeps it tied, it remains under his control, and if he lets it loose, it goes away."
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 4845