The Prophet ﷺ said: A believer who recites the Qur'an is like a citron whose fragrance is sweet and whose taste is sweet, a believer who does not recite the Qur'an is like a date which has no fragrance but has sweet taste, a profligate who recites the Qur'an is like basil whose fragrance is sweet but whose taste is bitter, and the profligate who does not recite the Qur'an is like the colocynth which has a bitter taste and has not fragrance. A good companion is like a man who has musk; if nothing of it goes to you, its fragrance will (certainly) go to you; and a bad companion is like a man who has bellows; if its (black) root does not go to you, its smoke will (certainly) go to you.  

قَالَ رَسُولُ اللَّهِ ﷺ مَثَلُ الْمُؤْمِنِ الَّذِي يَقْرَأُ الْقُرْآنَ مَثَلُ الأُتْرُجَّةِ رِيحُهَا طَيِّبٌ وَطَعْمُهَا طَيِّبٌ وَمَثَلُ الْمُؤْمِنِ الَّذِي لاَ يَقْرَأُ الْقُرْآنَ كَمَثَلِ التَّمْرَةِ 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 وَمَثَلُ الْجَلِيسِ الصَّالِحِ كَمَثَلِ صَاحِبِ الْمِسْكِ إِنْ لَمْ يُصِبْكَ مِنْهُ شَىْءٌ أَصَابَكَ مِنْ رِيحِهِ وَمَثَلُ جَلِيسِ السُّوءِ كَمَثَلِ صَاحِبِ الْكِيرِ إِنْ لَمْ يُصِبْكَ مِنْ سَوَادِهِ أَصَابَكَ مِنْ دُخَانِهِ  

Anas said: We used tell one another that a good companion is like... He then transmitted the rest of the tradition.  

عَنِ النَّبِيِّ ﷺ بِهَذَا الْكَلاَمِ الأَوَّلِ إِلَى قَوْلِهِ وَطَعْمُهَا مُرٌّ وَزَادَ ابْنُ مُعَاذٍ قَالَ قَالَ أَنَسٌ وَكُنَّا نَتَحَدَّثُ أَنَّ مَثَلَ جَلِيسِ الصَّالِحِ وَسَاقَ بَقِيَّةَ الْحَدِيثِ  

The tradition mentioned above has also been transmitted by Anas b. Malik from the Prophet ﷺ through a different chain of narrators in a similar way.  

عَنِ النَّبِيِّ ﷺ قَالَ مَثَلُ الْجَلِيسِ الصَّالِحِ فَذَكَرَ نَحْوَهُ  

The Prophet ﷺ said: Associate only with a believer, and let only a God-fearing man eat your meals.  

عَنِ النَّبِيِّ ﷺ قَالَ لاَ تُصَاحِبْ إِلاَّ مُؤْمِنًا وَلاَ يَأْكُلْ طَعَامَكَ إِلاَّ تَقِيٌّ  

The Prophet ﷺ said: A man follows the religion of his friend; so each one should consider whom he makes his friend.  

أَنَّ النَّبِيَّ ﷺ قَالَ الرَّجُلُ عَلَى دِينِ خَلِيلِهِ فَلْيَنْظُرْ أَحَدُكُمْ مَنْ يُخَالِلُ  

The spirits are in marshaled hosts; those who know one another will be friendly, and those who do not, will keep apart.  

الأَرْوَاحُ جُنُودٌ مُجَنَّدَةٌ فَمَا تَعَارَفَ مِنْهَا ائْتَلَفَ وَمَا تَنَاكَرَ مِنْهَا اخْتَلَفَ