Musannaf Ibn Abi Shayba 22:261

'Affan narrated to us, he said: Hammam narrated to us, he said: Qatadah narrated to us, from Anas, that Abu Musa narrated to him, from the Prophet (may Allah bless him and grant him peace), who said: "The likeness of the believer who does not recite the Qur'an is like the date; its taste is good, but it has no scent. And the likeness of the believer who recites the Qur'an is like the citron; it is good in taste and good in scent. And the likeness of the wicked person who does not recite the Qur'an is like the colocynth; its taste is bitter, and it has no scent."