Al-Mundhiri records in his book al-Targhib wal-Tarhib:

التَّرْغِيب فِي تعاهد الْقُرْآن وتحسين الصَّوْت بِهِ

Encouragement to commit to the Quran and beautify one’s voice for it.

Source: al-Targhīb wal-Tarhīb 2/236

Abdullah ibn Umar reported: The Messenger of Allah, peace and blessings be upon him, said,

إِنَّمَا مَثَلُ صَاحِبِ الْقُرْآنِ كَمَثَلِ الْإِبِلِ الْمُعَقَّلَةِ إِنْ عَاهَدَ عَلَيْهَا أَمْسَكَهَا وَإِنْ أَطْلَقَهَا ذَهَبَتْ

Verily, the parable of the companion of the Quran is that of a tied camel. If he is committed to it, he will keep it. If he releases it, he will lose it.

Source: Ṣaḥīḥ al-Bukhārī 5031, Grade: Muttafaqun Alayhi

Ibn Mas’ud reported: The Messenger of Allah, peace and blessings be upon him, said:

بِئْسَ مَا لأَحَدِهِمْ أَنْ يَقُولَ نَسِيتُ آيَةَ كَيْتَ وَكَيْتَ بَلْ نُسِّيَ وَاسْتَذْكِرُوا الْقُرْآنَ فَإِنَّهُ أَشَدُّ تَفَصِّيًا مِنْ صُدُورِ الرِّجَالِ مِنَ النَّعَمِ

Wretched is one who says: I have forgotten such a verse. Rather, he was made to forget it. Strive to remember the Quran, for it is quicker to escape the hearts of men than camels.

Source: Ṣaḥīḥ al-Bukhārī 5032, Grade: Muttafaqun Alayhi

Abu Musa reported: The Messenger of Allah, peace and blessings be upon him, said:

تَعَاهَدُوا الْقُرْآنَ فَوَالَّذِي نَفْسِي بِيَدِهِ لَهُوَ أَشَدُّ تَفَصِّيًا مِنْ الْإِبِلِ فِي عُقُلِهَا

Be committed to the Quran. By the One in whose hand is my soul, it can leave you faster than a camel from its reins.

Source: Ṣaḥīḥ al-Bukhārī 5033, Grade: Muttafaqun Alayhi

Abu Huraira reported: The Messenger of Allah, peace and blessings be upon him, said:

مَا أَذِنَ اللَّهُ لِشَيْءٍ مَا أَذِنَ لِنَبِيٍّ حَسَنِ الصَّوْتِ يَتَغَنَّى بِالْقُرْآنِ يَجْهَرُ بِهِ

Allah does not listen to anything as he does to the beautiful voice of a prophet, reciting the Quran aloud pleasantly.

Source: Ṣaḥīḥ al-Bukhārī 7544, Grade: Muttafaqun Alayhi

Al-Bara ibn ‘Azib reported: The Messenger of Allah, peace and blessings be upon him, said:

زَيِّنُوا الْقُرْآنَ بِأَصْوَاتِكُمْ

Beautify the Quran with your voices.

Source: Sunan Abī Dāwūd 1468, Grade: Sahih

Jabir reported: The Messenger of Allah, peace and blessings be upon him, said:

إِنَّ مِنْ أَحْسَنِ النَّاسِ صَوْتًا بِالْقُرْآنِ الَّذِي إِذَا سَمِعْتُمُوهُ يَقْرَأُ حَسِبْتُمُوهُ يَخْشَى اللَّهَ

Among people who recite the Quran with the best voice are those who, when you hear them, you consider them fearful of Allah.

Source: Sunan Ibn Mājah 1339, Grade: Sahih

Abu Lubabah reported: The Messenger of Allah, peace and blessings be upon him, said:

لَيْسَ مِنَّا مَنْ لَمْ يَتَغَنَّ بِالْقُرْآنِ

He is not one of us who does not recite the Quran in a pleasant voice.

Source: Sunan Abī Dāwūd 1471, Grade: Jayyid

Fadalah ibn ‘Ubayd reported: The Messenger of Allah, peace and blessings be upon him, said:

لَلَّهُ أَشَدُّ أَذَنًا إِلَى الرَّجُلِ الْحَسَنِ الصَّوْتِ بِالْقُرْآنِ يَجْهَرُ بِهِ مِنْ صَاحِبِ الْقَيْنَةِ إِلَى قَيْنَتِهِ

Allah listens more intently to a man reciting the Quran aloud in a beautiful voice than an employer of singers listens to his singers.

Source: Sunan Ibn Mājah 1340, Grade: Sahih