Musnad Ahmad 788:180

Yahya ibn Sa'id narrated to us, Shu'bah narrated to us, from Qatadah, from Anas, from Abu Musa, from the Prophet, peace and blessings of Allah be upon him, who said: "The likeness of the believer who recites the Quran is like the citron (utrujjah): its taste is good and its scent is good. And the likeness of the believer who does not recite the Quran is like the date: its taste is good and it has no scent. And the likeness of the hypocrite who recites the Quran is like the basil (rayhanah): its scent is good and it has no taste." And Yahya said: "Sometimes [he said] its taste is bitter." "And the likeness of the hypocrite who does not recite the Quran is like the colocynth (hanthalah): it has no scent and its taste is foul."