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

الترغيب في الصمت إلا عن خير والترهيب من كثرة الكلام

Encouragement to be silent except for good words, and discouragement of speaking too much.

Source: al-Targhīb wal-Tarhīb 3/521

Abu Musa reported: They said, “O Messenger, of Allah, whose Islam is best?” The Messenger of Allah, peace and blessings be upon him, said:

مَنْ سَلِمَ الْمُسْلِمُونَ مِنْ لِسَانِهِ وَيَدِهِ

One from who tongue and hand Muslims are safe.

Source: Ṣaḥīḥ al-Bukhārī 11, Grade: Muttafaqun Alayhi

Abdullah bin Amr reported: The Prophet, peace and blessings be upon him, said:

الْمُسْلِمُ مَنْ سَلِمَ الْمُسْلِمُونَ مِنْ لِسَانِهِ وَيَدِهِ وَالْمُهَاجِرُ مَنْ هَجَرَ مَا نَهَى اللَّهُ عَنْهُ

The Muslim is one from whose tongue and hand Muslims are safe. The emigrant is the one who abandons what Allah has forbidden.

Source: Ṣaḥīḥ al-Bukhārī 10, Grade: Muttafaqun Alayhi

Abdullah ibn Mas’ud reported: I said, “O Messenger of Allah, which deeds are best?” The Messenger of Allah, peace and blessings be upon him, said:

الصَّلَاةُ عَلَى مِيقَاتِهَا

Prayer on time.

I said, “Then what, O Messenger of Allah?” The Prophet said:

بِرُّ الْوَالِدَيْنِ

Good treatment of your parents.

I said, “Then what, O Messenger of Allah?” The Prophet said:

أَنْ يَسْلَمَ النَّاسُ مِنْ لِسَانِكَ

That people are safe from your tongue.

Source: al-Mu’jam al-Kabīr 9687, Grade: Sahih

Al-Bara’ reported: A bedouin came and he said, “O Prophet of Allah, teach me a deed that will admit me into Paradise.” The Prophet, peace and blessings be upon him, said:

لَئِنْ كُنْتَ أَقَصَرْتَ الْخُطْبَةَ لَقَدْ أَعْرَضْتَ الْمَسْأَلَةَ أَعْتِقِ النَّسَمَةَ وَفُكَّ الرَّقَبَةَ

Although you have expressed it in few words, the matter is broad. Emancipate an individual. Free a slave.

The man said, “Are they not the same?” The Prophet said:

لا عِتْقُ النَّسَمَةِ أَنْ تَعْتِقَ النَّسَمَةَ وَفَكُّ الرَّقَبَةِ أَنْ تُعِينَ عَلَى الرَّقَبَةِ وَالْمَنِيحَةُ الرَّغُوبُ وَالْفَيْءُ عَلَى ذِي الرَّحِمِ فَإِنْ لَمْ تُطِقْ ذَلِكَ فَأْمُرْ بِالْمَعْرُوفِ وَانْهَ عَنِ الْمُنْكَرِ فَإِنْ لَمْ تُطِقْ ذَلِكَ فَكُفَّ لِسَانَكَ إِلا مِنْ خَيْرٍ

No, emancipating an individual is that you emancipate him yourself, and freeing a slave is that you help someone else free him. Lend a healthy animal to be milked, and treat your relatives well. If you cannot do that, enjoin good and forbid evil. If you cannot do that, hold back your tongue except to say good words.

Source: al-Adab al-Mufrad 69, Grade: Sahih

‘Uqbah ibn ‘Amir reported: I said, “O Messenger of Allah, what will save us?” The Messenger of Allah, peace and blessings be upon him, said:

أَمْسِكْ عَلَيْكَ لِسَانَكَ وَلْيَسَعْكَ بَيْتُكَ وَابْكِ عَلَى خَطِيئَتِكَ

Control your tongue, let your house be enough for you, and weep for your sins.

Source: Sunan al-Tirmidhī 2406, Grade: Sahih

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

طُوبَى لِمَنْ مَلَكَ لِسَانَهُ وَوَسِعَهُ بَيْتُهُ وَبَكَى عَلَى خَطِيئَتِهِ

Blessed is one who controls his tongue, whose house is spacious, and who weeps for his sins.

Source: al-Mu’jam al-Awsaṭ 2398, Grade: Hasan

Sahl ibn Sa’d reported: The Messenger of Allah, peace and blessings be upon him, said:

مَنْ يَضْمَنْ لِي مَا بَيْنَ لَحْيَيْهِ وَمَا بَيْنَ رِجْلَيْهِ أَضْمَنْ لَهُ الْجَنَّةَ

Whoever guarantees for me what is between his jaws and his legs, I can guarantee for him Paradise.

Source: Ṣaḥīḥ al-Bukhārī 6109, Grade: Sahih

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

مَنْ وَقَاهُ اللَّهُ شَرَّ مَا بَيْنَ لَحْيَيْهِ وَشَرَّ مَا بَيْنَ رِجْلَيْهِ دَخَلَ الْجَنَّةَ

Whomever Allah protects from the evil between his jaws and his legs, he will enter Paradise.

Source: Sunan al-Tirmidhī 2409, Grade: Sahih

‘Anbas ibn ‘Uqbah reported: Abdullah ibn Mas’ud, may Allah be pleased with him, said:

وَاللَّهِ الَّذِي لَا إِلَهَ غَيْرُهُ مَا عَلَى ظَهْرِ الْأَرْضِ شَيْءٌ أَحْوَجُ إِلَى طُولِ سِجْنٍ مِنْ لِسَانٍ

By Allah, besides whom there is no God, nothing on earth is in greater need of a lengthy prison sentence than the tongue.

Source: al-Mu’jam al-Kabīr 8745, Grade: Sahih

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

مَنْ حَفِظَ مَا بَيْنَ فُقْمَيْهِ وَفَرْجَهُ دَخَلَ الْجَنَّةَ

Whoever guards what is between his jaws and guards his chastity, he will enter Paradise.

Source: Musnad Aḥmad 19065, Grade: Sahih

Abu Rafi’ reported: The Prophet, peace and blessings be upon him, said:

مَنْ حَفِظَ مَا بَيْنَ فُقْمَيْهِ وَفَخِذَيْهِ دَخَلَ الْجَنَّةَ

Whoever guards what is between his jaws and his thighs, he will enter Paradise.

Source: al-Mu’jam al-Kabīr 914, Grade: Jayyid

Sufyan ibn Abdullah reported: I said, “O Messenger of Allah, tell me of a matter I can depend upon?” The Messenger of Allah, peace and blessings be upon him, said:

قُلْ رَبِّيَ اللَّهُ ثُمَّ اسْتَقِمْ

Say: My Lord is Allah. Then, remain upright.

I said, “O Messenger of Allah, what do you fear most for me?” The Prophet pointed to his tongue and then he said:

هَذَا

This.

Source: Sunan al-Tirmidhī 2410, Grade: Sahih

Al-Harith ibn Hisham reported: He said, “Tell me of a matter I can hold firmly.” The Messenger of Allah, peace and blessings be upon him, pointed to his tongue and he said:

امْلِكْ هَذَا

Control this.

Source: al-Mu’jam al-Kabīr 3348, Grade: Sahih

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

لَا يَسْتَقِيمُ إِيمَانُ عَبْدٍ حَتَّى يَسْتَقِيمَ قَلْبُهُ وَلَا يَسْتَقِيمُ قَلْبُهُ حَتَّى يَسْتَقِيمَ لِسَانُهُ وَلَا يَدْخُلُ رَجُلٌ الْجَنَّةَ لَا يَأْمَنُ جَارُهُ بَوَائِقَهُ

The faith of a servant is not upright until his heart is upright, and his heart is not upright until his tongue is upright. A man will not enter Paradise if his neighbor is not secure from his evil.

Source: Musnad Aḥmad 12636, Grade: Hasan

Mu’adh ibn Jabal reported: I said, “O Messenger of Allah, tell me of a deed that will admit me into Paradise and keep me away from the Hellfire.” The Messenger of Allah, peace and blessings be upon him, said:

لَقَدْ سَأَلْتَنِي عَنْ عَظِيمٍ وَإِنَّهُ لَيَسِيرٌ عَلَى مَنْ يَسَّرَهُ اللَّهُ عَلَيْهِ تَعْبُدُ اللَّهَ وَلَا تُشْرِكْ بِهِ شَيْئًا وَتُقِيمُ الصَّلَاةَ وَتُؤْتِي الزَّكَاةَ وَتَصُومُ رَمَضَانَ وَتَحُجُّ الْبَيْتَ

You have asked about an enormous matter, yet it is easy upon those for whom Allah makes it easy. Worship Allah and do not associate anything with him, establish the prayer, give the charity, fast the month of Ramadan, and perform pilgrimage to the House. 

Then, the Prophet said:

أَلَا أَدُلُّكَ عَلَى أَبْوَابِ الْخَيْرِ الصَّوْمُ جُنَّةٌ وَالصَّدَقَةُ تُطْفِئُ الْخَطِيئَةَ كَمَا يُطْفِئُ الْمَاءُ النَّارَ وَصَلَاةُ الرَّجُلِ مِنْ جَوْفِ اللَّيْلِ

Shall I not tell you about the gates of goodness? Fasting is a shield, charity extinguishes sins as water extinguishes fire, and the prayer of a man in the late night.

Then, the Prophet recited the verse:

تَتَجَافَى جُنُوبُهُمْ عَنْ الْمَضَاجِعِ حَتَّى بَلَغَ يَعْمَلُونَ

They arise from their beds and supplicate to their Lord in fear and hope. They spend from what We have provided them, for no soul knows what has been hidden for them of comfort as reward for what they used to do. (32:16)

Then, the Prophet said:

أَلَا أُخْبِرُكَ بِرَأْسِ الْأَمْرِ كُلِّهِ وَعَمُودِهِ وَذِرْوَةِ سَنَامِهِ

Shall I not tell you about the head of the matter and its peak?

I said, “Of course, O Messenger of Allah.” The Prophet said:

رَأْسُ الْأَمْرِ الْإِسْلَامُ وَعَمُودُهُ الصَّلَاةُ وَذِرْوَةُ سَنَامِهِ الْجِهَادُ

The head of the matter is Islam, its pillar is prayer, and jihad is its peak.

Then the Prophet said:

أَلَا أُخْبِرُكَ بِمَلَاكِ ذَلِكَ كُلِّهِ

Shall I not tell you how to achieve all of this?

I said, “Yes, O Messenger of Allah.” The Prophet pointed to his tongue and he said:

كُفَّ عَلَيْكَ هَذَا

Restrain this.

I said, “O Prophet of Allah, will what we say be held against us?” The Prophet said:

ثَكِلَتْكَ أُمُّكَ يَا مُعَاذُ وَهَلْ يَكُبُّ النَّاسَ فِي النَّارِ عَلَى وُجُوهِهِمْ أَوْ عَلَى مَنَاخِرِهِمْ إِلَّا حَصَائِدُ أَلْسِنَتِهِمْ

May your mother be bereaved of you, O Mu’adh! Is there anything that topples people onto their faces in the Hellfire but the harvest of their tongues?

Source: Sunan al-Tirmidhī 2616, Grade: Sahih

Aswad ibn Asram reported: I said, “O Messenger of Allah, instruct me.” The Messenger of Allah, peace and blessings be upon him, said:

هَلْ تَمْلِكُ لِسَانَكَ

Can you control your tongue?

I said, “But what do I control if I cannot control my tongue?” The Prophet said:

فَهَلْ تَمْلِكُ يَدَكَ

Can you control your hands?

I said, “But what do I control if I cannot control my hands?” The Prophet said:

فَلا تَقُلْ بِلِسَانِكَ إِلا مَعْرُوفًا وَلا تَبْسُطْ يَدَكَ إِلا إِلَى خَيْرٍ

Do not say anything on your tongue except what is right, and do not stretch out your hand except to do good.

Source: Shu’ab al-Imān 2867, Grade: Sahih

Abu Dharr reported: I said, “O Messenger of Allah, instruct me.” The Prophet, peace and blessings be upon him, said:

أَوْصَيْكَ بِتَقْوَى اللَّهِ عَزَّ وَجَلَّ فَإِنَّهُ أَزْيَنُ لأَمْرِكَ كُلِّهِ

I advise you to be mindful of Allah Almighty, for it will beautify all of your affairs.

I said, “Tell me more.” The Prophet said:

عَلَيْكَ بِتِلاوَةِ الْقُرْآنِ وَذِكْرِ اللَّهِ عَزَّ وَجَلَّ فَإِنَّهُ ذِكْرٌ لَكَ فِي السَّمَاءِ وَنُورٌ لَكَ فِي الأَرْضِ

You must recite the Quran and remember Allah Almighty, for you will be mentioned in heaven and you will have light upon earth.

I said, “Tell me more.” The Prophet said:

عَلَيْكَ بِطُولِ الصَّمْتِ فَإِنَّهُ مَطْرَدَةٌ لِلشَّيْطَانِ وَعَوْنٌ لَكَ عَلَى أَمْرِ دِينِكَ

You must observe long periods of silence, for it will drive away Satan and help you in the matter of your religion.

I said, “Tell me more.” The Prophet said:

إِيَّاكَ وَكَثْرَةَ الضَّحِكِ فَإِنَّهُ يُمِيتُ الْقَلْبَ وَيَذْهَبُ بِنُورِ الْوَجْهِ

Beware of too much laughter, for it will deaden the heart and take away the light on your face.

I said, “Tell me more.” The Prophet said:

قُلِ الْحَقَّ وَإِنْ كَانَ مُرًّا

Speak the truth, even if it is bitter.

I said, “Tell me more.” The Prophet said:

لا تَخَفْ فِي اللَّهِ لَوْمَةَ لائِمٍ

Do not fear the blame of any critic in the matter of Allah.

Source: Shu’ab al-Imān 4592, Grade: Sahih li ghayrihi

Abu Sa’id al-Khudri reported: A man came to the Messenger of Allah, peace and blessings be upon him, and he said, “O Messenger of Allah, instruct me.” The Prophet said:

عَلَيْكَ بِتَقْوَى اللَّهِ فَإِنَّهَا جِمَاعُ كُلِّ خَيْرٍ وَعَلَيْكَ بِالْجِهَادِ فِي سَبِيلِ اللَّهِ فَإِنَّهَا رَهْبَانِيَّةُ الْمُسْلِمِينَ وَعَلَيْكَ بِذِكْرِ اللَّهِ وَتِلاوَةِ كِتَابِهِ فَإِنَّهُ نُورٌ لَكَ فِي الأَرْضِ وَذِكْرٌ لَكَ فِي السَّمَاءِ وَاخْزُنْ لِسَانَكَ إِلا مِنْ خَيْرٍ فَإِنَّكَ بِذَلِكَ تَغْلِبُ الشَّيْطَانَ

You must fear Allah, as it is the sum of all good. You must wage jihad in the way of Allah, as it is the monasticism of the Muslims. You must remember Allah and recite his book, as it will be a light for you on earth and your mention in the heavens. You must hold your tongue except for what is good, as by it you will defeat Satan.

Source: al-Mu’jam al-Ṣaghīr 947, Grade: Sahih li ghayrihi

Mu’adh ibn Jabal reported: He said, “O Messenger of Allah, instruct me.” The Messenger of Allah, peace and blessings be upon him, said:

اعْبُدِ اللَّهَ كَأَنَّكَ تَرَاهُ وَاعْدُدْ نَفْسَكَ فِي الْمَوْتَى وَإِنْ شِئْتَ أَنْبَأْتُكَ بِمَا هُوَ أَمْلَكُ بِكَ مِنْ هَذَا كُلِّهِ

Worship Allah as if you can see him and prepare yourself for death. If you wish, I will tell you what should be reined in more than all of that.

The Prophet pointed to his tongue and he said:

هَذَا

It is this.

Source: al-Ṣamt li Ibn Abī Dunyā 22, Grade: Jayyid

Abu Sa’id al-Khudri reported: The Prophet, peace and blessings be upon him, said:

إِذَا أَصْبَحَ ابْنُ آدَمَ فَإِنَّ الْأَعْضَاءَ كُلَّهَا تُكَفِّرُ اللِّسَانَ فَتَقُولُ اتَّقِ اللَّهَ فِينَا فَإِنَّمَا نَحْنُ بِكَ فَإِنْ اسْتَقَمْتَ اسْتَقَمْنَا وَإِنْ اعْوَجَجْتَ اعْوَجَجْنَا

When the son of Adam wakes up in the morning, all of his limbs defer to the tongue and they say: Fear Allah regarding us, for we are only a part of you. If you are upright, we are upright. If you are crooked, we are crooked.

Source: Sunan al-Tirmidhī 2407, Grade: Sahih

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

أَكْثَرُ خَطَايَا ابنِ آدَمَ فِي لِسَانِهِ

Most of the sins of the children of Adam are on their tongues.

And Ibn Mas’ud, may Allah be pleased with him, said:

يَا لِسَانُ قُلْ خَيْرًا تَغْنَمْ وَاسْكُتْ عَنْ شَرٍّ تَسْلَمْ مِنْ قَبْلِ أَنْ تَنْدَمَ

O tongue! Speak goodness and be rewarded, or remain silent and be safe, lest you become regretful.

Source: al-Mu’jam al-Kabīr 10300, Grade: Sahih

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

لَيْسَ شَيْءٌ مِنَ الْجَسَدِ إِلا وَهُوَ يَشْكُو ذَرَبَ اللِّسَانِ

There is no limb on the body but that it complains of the sharpness of the tongue.

Source: Musnad Abī Ya’lá 5, Grade: Sahih

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

مَنْ صَمَتَ نَجَا

Whoever is silent has been saved.

Source: Sunan al-Tirmidhī 2501, Grade: Sahih

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

إِنَّ الْعَبْدَ لَيَتَكَلَّمُ بِالْكَلِمَةِ يَنْزِلُ بِهَا فِي النَّارِ أَبْعَدَ مَا بَيْنَ الْمَشْرِقِ وَالْمَغْرِبِ

Verily, the servant may speak a single word for which he plummets into the Hellfire farther than the distance between East and West.

Source: Ṣaḥīḥ al-Bukhārī 6112, Grade: Muttafaqun Alayhi

In another narration, the Prophet said:

إِنَّ الْعَبْدَ لَيَتَكَلَّمُ بِالْكَلِمَةِ مِنْ رِضْوَانِ اللَّهِ لَا يُلْقِي لَهَا بَالًا يَرْفَعُهُ اللَّهُ بِهَا دَرَجَاتٍ وَإِنَّ الْعَبْدَ لَيَتَكَلَّمُ بِالْكَلِمَةِ مِنْ سَخَطِ اللَّهِ لَا يُلْقِي لَهَا بَالًا يَهْوِي بِهَا فِي جَهَنَّمَ

Verily, a servant may speak a word pleasing to Allah, thinking nothing of it, yet by it Allah raises his status by a degree. Verily, a servant may speak a word displeasing to Allah, thinking nothing of it, yet by it he plummets into Hell.

Source: Ṣaḥīḥ al-Bukhārī 6113, Grade: Sahih

Bilal ibn al-Harith reported: The Messenger of Allah, peace and blessings be upon him, said:

إِنَّ أَحَدَكُمْ لَيَتَكَلَّمُ بِالْكَلِمَةِ مِنْ رِضْوَانِ اللَّهِ مَا يَظُنُّ أَنْ تَبْلُغَ مَا بَلَغَتْ فَيَكْتُبُ اللَّهُ لَهُ بِهَا رِضْوَانَهُ إِلَى يَوْمِ يَلْقَاهُ وَإِنَّ أَحَدَكُمْ لَيَتَكَلَّمُ بِالْكَلِمَةِ مِنْ سَخَطِ اللَّهِ مَا يَظُنُّ أَنْ تَبْلُغَ مَا بَلَغَتْ فَيَكْتُبُ اللَّهُ عَلَيْهِ بِهَا سَخَطَهُ إِلَى يَوْمِ يَلْقَاهُ

Verily, one of you speaks a word pleasing to Allah, thinking it does not amount to much, yet by it Allah decrees his pleasure with him until the day he meets him. Verily, one of you speaks a word displeasing to Allah, thinking it does not amount to much, yet Allah decrees his displeasure with him until the day he meets him.

Source: Sunan al-Tirmidhī 2319, Grade: Sahih

Al-Mughirah ibn Sha’bah reported: The Prophet, peace and blessings be upon him, said:

إِنَّ اللَّهَ حَرَّمَ عَلَيْكُمْ عُقُوقَ الْأُمَّهَاتِ وَمَنْعًا وَهَاتِ وَوَأْدَ الْبَنَاتِ وَكَرِهَ لَكُمْ قِيلَ وَقَالَ وَكَثْرَةَ السُّؤَالِ وَإِضَاعَةَ الْمَالِ

Verily, Allah has forbidden you from disobeying your mothers, withholding charity, demanding from others, and burying your daughters alive. Allah disapproves that you spread talebearing and gossip, ask many unnecessary questions, and waste your wealth.

Source: Ṣaḥīḥ al-Bukhārī 5630, Grade: Muttafaqun Alayhi

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

إِنَّ مِنْ حُسْنِ إِسْلَامِ الْمَرْءِ تَرْكَهُ مَا لَا يَعْنِيهِ

Verily, part of perfection in Islam is for a person to leave what does not concern him.

Source: Sunan al-Tirmidhī 2318, Grade: Sahih li ghayri

Anas reported: A man among the companions of the Prophet passed away and another man said, “Receive glad tidings of Paradise!” The Messenger of Allah, peace and blessings be upon him, said:

أَوَلَا تَدْرِي فَلَعَلَّهُ تَكَلَّمَ فِيمَا لَا يَعْنِيهِ أَوْ بَخِلَ بِمَا لَا يَنْقُصُهُ

Certainly, you do not know for sure! Perhaps he spoke of what does not concern him, or he was miserly with what would not disadvantage him.

Source: Sunan al-Tirmidhī 2316, Grade: Sahih li ghayri