Hadith 6
Ibn Mas’ud reported: The Messenger of Allah, peace and blessings be upon him, said:
لَيْسَ الْمُؤْمِنُ بِالطَّعَّانِ وَلَا اللَّعَّانِ وَلَا الْفَاحِشِ وَلَا الْبَذِيءِ
The believer does not insult others, does not curse others, is not vulgar, and is not shameless.
Source: Sunan al-Tirmidhī 1977, Grade: Sahih