Sahih Bukhari Volume 6, Book 66, Hadith 5022

حَدَّثَنَا هُدْبَةُ بْنُ خَالِدٍ أَبُو خَالِدٍ، حَدَّثَنَا هَمَّامٌ، حَدَّثَنَا قَتَادَةُ، حَدَّثَنَا أَنَسٌ، عَنْ أَبِي مُوسَى، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ ‏"‏ مَثَلُ الَّذِي يَقْرَأُ الْقُرْآنَ كَالأُتْرُجَّةِ طَعْمُهَا طَيِّبٌ وَرِيحُهَا طَيِّبٌ وَالَّذِي لاَ يَقْرَأُ الْقُرْآنَ كَالتَّمْرَةِ طَعْمُهَا طَيِّبٌ وَلاَ رِيحَ لَهَا، وَمَثَلُ الْفَاجِرِ الَّذِي يَقْرَأُ الْقُرْآنَ كَمَثَلِ الرَّيْحَانَةِ رِيحُهَا طَيِّبٌ وَطَعْمُهَا مُرٌّ، وَمَثَلُ الْفَاجِرِ الَّذِي لاَ يَقْرَأُ الْقُرْآنَ كَمَثَلِ الْحَنْظَلَةِ طَعْمُهَا مُرٌّ وَلاَ رِيحَ لَهَا ‏"

Narrated By Abu Musa Al-Ash'ari : The Prophet said, "The example of him (a believer) who recites the Qur'an is like that of a citron which tastes good and smells good. And he (a believer) who does not recite the Qur'an is like a date which is good in taste but has no smell. And the example of a dissolute wicked person who recites the Qur'an is like the Raihana (sweet basil) which smells good but tastes bitter. And the example of a dissolute wicked person who does not recite the Qur'an is like the colocynth which tastes bitter and has no smell.