Al-Mundhiri recorded the following chapter in his book Al-Targhib wal-Tarhib:

الترغيب في السواك وما جاء في فضله

Encouragement to use the toothstick and what has been related of its virtues.

Source: al-Targhīb wal-Tarhīb 1/164

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

لَوْلَا أَنْ أَشُقَّ عَلَى أُمَّتِي أَوْ عَلَى النَّاسِ لَأَمَرْتُهُمْ بِالسِّوَاكِ مَعَ كُلِّ صَلَاة

Were it not a burden upon my nation, I would have ordered them to use the toothstick before every prayer.

Source: Ṣaḥīḥ al-Bukhārī 847, Grade: Muttafaqun Alayhi

In another narration, the Prophet said:

لَأَمَرْتُهُمْ بِالسِّوَاكِ مَعَ كُلِّ وُضُوءٍ

I would have ordered them to use the toothstick with every ablution.

Source: Musnad Aḥmad 7461, Grade: Sahih

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

لَوْلَا أَنْ أَشُقَّ عَلَى أُمَّتِي لَأَمَرْتُهُمْ بِالسِّوَاكِ مَعَ كُلِّ وُضُوءٍ

Were it not hardship for my nation, I would have commanded them to use the toothstick with every ablution.

Source: al-Mu’jam al-Awsaṭ 1260, Grade: Sahih

Al-‘Abbas reported: They entered upon the Messenger of Allah, peace and blessings be upon him, without having brushed their teeth. The Prophet said:

تَدْخُلُونَ عَلَيَّ قُلْحًا اسْتَاكُوا فَلَوْلَا أَنْ أَشُقَّ عَلَى أُمَّتِي لَفَرَضْتُ السِّوَاكَ عِنْدَ كُلِّ صَلَاةٍ كَمَا فَرَضْتُ عَلَيْهِمُ الْوُضُوءَ

You enter upon me with unclean teeth? Go use the toothstick. Were it not hardship for my nation, I would have obligated them to use the toothstick at every prayer, just as I obligated them to perform ablution.

Source: Musnad al-Bazzār 1303, Grade: Sahih

Aisha reported: The Prophet, peace and blessings be upon him, said:

السِّوَاكُ مَطْهَرَةٌ لِلْفَمِ مَرْضَاةٌ لِلرَّبِّ

The toothstick is cleansing for the mouth and pleasing to the Lord.

Source: Sunan al-Nasā’ī 5, Grade: Sahih

Ibn Umar reported: The Prophet, peace and blessings be upon him, said:

عَلَيْكُمْ بِالسِّوَاكِ فَإِنَّهُ مَطْيَبَةٌ لِلْفَمِ وَمَرْضَاةٌ لِلرَّبِّ

You must use the toothstick, as it is pleasant for the mouth and pleasing to the Lord.

Source: Musnad Aḥmad 5831, Source: Sahih

Shurayh reported: I asked Aisha, saying, “What was the first thing the Prophet, peace and blessings be upon him, did when he entered his house?” Aisha said:

بِالسِّوَاكِ

Use the toothstick.

Source: Ṣaḥīḥ Muslim 253, Grade: Sahih

Hudhayfah reported:

كَانَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِذَا قَامَ مِنْ اللَّيْلِ يَشُوصُ فَاهُ بِالسِّوَاكِ

When the Prophet, peace and blessings be upon him, arose at night, he would clean his mouth with the toothstick.

Source: Ṣaḥīḥ al-Bukhārī 243, Grade: Muttafaqun Alayhi

Ibn Abbas reported:

كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يُصَلِّي بِاللَّيْلِ رَكْعَتَيْنِ رَكْعَتَيْنِ ثُمَّ يَنْصَرِفُ فَيَسْتَاكُ

The Messenger of Allah, peace and blessings be upon him, would pray at night in cycles two by two, then he used the toothstick after he finished.

Source: Sunan Ibn Mājah 288, Grade: Sahih

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

لَقَدْ أُمِرْتُ بِالسِّوَاكِ حَتَّى ظَنَنْتُ أَنَّهُ سَيَنْزِلُ بِهِ عَلَيَّ قُرْآنٌ أَوْ وَحْيٌ

I have ordered use of the toothstick so often that I thought something of it would be sent down to me in the Quran or revealed to me.

Source: Musnad Aḥmad 2998, Grade: Sahih

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

أُمِرْتُ بِالسِّوَاكِ حَتَّى خَشِيتُ أَنْ أَدْرَدَ

I was ordered to use the toothstick so often that I was afraid my teeth might fall out.

Source: Musnad al-Bazzār 2455, Grade: Sahih

Ali reported: The Prophet, peace and blessings be upon him, said:

إِنَّ الْعَبْدَ إِذَا تَسَوَّكَ ثُمَّ قَامَ يُصَلِّي قَامَ الْمَلَكُ خَلْفَهُ فَتَسَمَّعَ لِقِرَاءَتِهِ فَيَدْنُو مِنْهُ حَتَّى يَضَعَ فَاهُ عَلَى فِيهِ فَمَا يَخْرُجُ مِنْ فِيهِ شَيْءٌ مِنَ الْقُرْآنِ إِلا صَارَ فِي جَوْفِ الْمَلَكِ فَطَهِّرُوا أَفْوَاهَكُمْ لِلْقُرْآنِ

Verily, when the servant uses the toothstick and then stands to pray, an angel stands behind him and listens to his recitation. The angel draws near until his mouth coincides with his and nothing of the Quran comes out of it but that it enters the heart of the angel. Thus, purify your mouths for the Quran.

Source: Musnad al-Bazzār 568, Grade: Hasan