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

الترهيب من النميمة

Discouragement of gossiping, talebearing.

Source: al-Targhīb wal-Tarhīb 3/495

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

لَا يَدْخُلُ الْجَنَّةَ قَتَّاتٌ

The talebearer will not enter Paradise.

Source: Ṣaḥīḥ al-Bukhārī 5709, Grade: Muttafaqun Alayhi

In another narration, the Prophet said:

لاَ يَدْخُلُ الْجَنَّةَ نَمَّامٌ

The gossip-monger will not enter Paradise.

Source: Ṣaḥīḥ Muslim 105, Grade: Sahih

Ibn Abbas reported: The Messenger of Allah, peace and blessings be upon him, passed by two graves and he said:

إِنَّهُمَا لَيُعَذَّبَانِ وَمَا يُعَذَّبَانِ فِي كَبِيرٍ أَمَّا هَذَا فَكَانَ لَا يَسْتَتِرُ مِنْ بَوْلِهِ وَأَمَّا هَذَا فَكَانَ يَمْشِي بِالنَّمِيمَةِ

Both of them are being punished, but not by a major sin. As for this man, he did not prevent his urine from soiling him. And as for this man, he would spread gossip.

Source: Ṣaḥīḥ al-Bukhārī 5705, Grade: Muttafaqun Alayhi

Abu Huraira reported: We were walking with the Messenger of Allah, peace and blessings be upon him, when we passed by two graves. The Prophet said:

مَا تَسْمَعُونَ مَا أَسْمَعُ

You cannot hear what I hear.

We said, “What is that, O Prophet of Allah?” The Prophet said:

هَذَانِ رَجُلانِ يُعَذَّبَانِ فِي قُبُورِهِمَا عَذَابًا شَدِيدًا فِي ذَنْبٍ هَيِّنٍ

These two men are being severely punished in their graves for a trivial matter.

We said, “What is that, O Prophet of Allah?” The Prophet said:

كَانَ أَحَدُهُمَا لا يَسْتَنْزِهُ مِنَ الْبَوْلِ وَكَانَ الآخَرُ يُؤْذِي النَّاسَ بِلِسَانِهِ وَيَمْشِي بَيْنَهُمْ بِالنَّمِيمَةِ

One of them did not take care to keep his garments clean of urine. The other harmed people with his tongue, carrying gossip between them.

Source: Ṣaḥīḥ Ibn Ḥibbān 831, Grade: Sahih

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

أَلَا أُخْبِرُكُمْ بِأَفْضَلَ مِنْ دَرَجَةِ الصِّيَامِ وَالصَّلَاةِ وَالصَّدَقَةِ

Shall I not tell you of what is better in degree than extra fasting, prayer, and charity?

They said, “Of course!” The Prophet said:

صَلَاحُ ذَاتِ الْبَيْنِ فَإِنَّ فَسَادَ ذَاتِ الْبَيْنِ هِيَ الْحَالِقَةُ

Reconciliation between people. Verily, corrupted relations between people is the razor.

Source: Sunan al-Tirmidhī 2509, Grade: Sahih

In another narration, the Prophet said:

الحَسَدُ وَالبَغْضَاءُ هِيَ الحَالِقَةُ لاَ أَقُولُ تَحْلِقُ الشَّعَرَ وَلَكِنْ تَحْلِقُ الدِّينَ

Envy and hatred are the razor. I do not say they shave hair. Rather, they shave away the religion.

Source: Sunan al-Tirmidhī 2510, Grade: Sahih

Asma’ bint Yazid reported: The Prophet, peace and blessings be upon him, said:

أَلا أُخْبِرُكُمْ بِخِيَارِكُمْ

Shall I not tell you about the best of you?

They said, “Of course.” The Prophet said:

إِذَا رُءُوا ذُكِرَ اللَّهُ أَفَلا أُخْبِرُكُمْ بِشِرَارِكُمْ

Those who, if they are seen, they remind you of Allah. Shall I not tell you about the worst of you?

They said, “Of course.” The Prophet said:

الْمَشَّاؤُونَ بِالنَّمِيمَةِ الْمُفْسِدُونَ بَيْنَ الأَحِبَّةِ الْبَاغُونَ الْبُرَآءَ الْعَنَتَ

Those who carry gossip and ruin relations between loves ones, seeking misery for the innocent.

Source: al-Adab al-Mufrad 321, Grade: Hasan

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

إِنَّ أَحَبَّكُمْ إِلَيَّ أَحْسَنُكُمْ أَخْلَاقًا الْمُوَطَّئُونَ أَكْنَافًا الَّذِينَ يَأْلَفُونَ وَيُؤْلَفُونَ وَأَبْغَضَكُمْ إِلَى اللَّهِ الْمَشَّاءُونَ بِالنَّمِيمَةِ الْمُفَرِّقُونَ بَيْنَ الْأَحِبَّةِ الْمُلْتَمِسُونَ لِلْبُرَآءِ الْعَنَتَ

Verily, the most beloved to me are those of you with the best character, soft in nature, friendly and befriended. The most hateful of you to Allah are those who spread gossip, who cause discord between loved ones and seek misery for the innocent.

Source: al-Mu’jam al-Awsaṭ 7693, Grade: Hasan li ghayrihi

In another narration, the Prophet said:

الْمُلْتَمِسُونَ لِلْبُرَآءِ الْعَنَتَ الْعَيْبَ

Seeking misery and finding faults with the innocent.

Source: al-Mu’jam al-Ṣaghīr 837, Grade: Hasan li ghayrihi

Abdur Rahman Ghanm reported: The Prophet, peace and blessings be upon him, said:

خِيَارُ عِبَادِ اللهِ الَّذِينَ إِذَا رُءُوا ذُكِرَ اللهُ وَشِرَارُ عِبَادِ اللهِ الْمَشَّاءُونَ بِالنَّمِيمَةِ الْمُفَرِّقُونَ بَيْنَ الْأَحِبَّةِ الْبَاغُونَ الْبُرَآءَ الْعَنَتَ

The best servants of Allah are those who remind you of Allah when they are seen. The worst servants of Allah are those who carry gossip, separating between loved ones and seeking misery for the innocent.

Source: Musnad Aḥmad 17998, Grade: Hasan li ghayrihi