that the Messenger of Allah (ﷺ) narrated: "The parable of the believer who recites the Quran is that of a citron, its fragrance is nice and its taste is nice. The parable of the believer who does not recite the Quran is that of a date, it has no smell but its taste is sweet. The parable of the hypocrite who recites the Quran is that of basil, its fragrance is nice but its taste is bitter. The parable of the hypocrite who does not recite the Quran is that of the colocynth, its smell is better and its taste is bitter.'"
Jami` at-Tirmidhi Book 44, Hadith 7