Fraud No. (28)_ Insulting a Muslim Is Immorality and Fighting Him Is Disbelief
Sahih Muslim 97
The Messenger of God said : Insulting a Muslim is an act of disobedience and fighting him is disbelief.
Sahih Muslim with Al-Nawawi’s explanation
Insulting in the language = cursing and speaking about a person’s honor in a way that defames him.
http://hadith.al-islam.com/Display/Display.asp?Doc=1&ID=63374&SearchText=Causes%20of%20Muslim%20Fusuq& SearchType =derivative&Scope=0,1,2,3,4,5,6,7,8&Offs et=0&SearchLevel=Allword
What is prohibited from cursing and swearing?
Etiquette
5584 Sahih al-Bukhari
on the authority of Abdullah who said that the Messenger of Allah said:Cursing a Muslimis transgression and fighting him is disbelief. Ghundar followed him on the authority of Shu’bah
http://hadith.al-islam.com/Display/Display.asp?Doc=0&ID=43102&SearchText =Cursing%20Muslim%20Fusuq& SearchType=derivative&Scope=0,1,2,3,4,5,6,7,8&Offs et=0&SearchLevel=Allword
The fear of the believer that his work will be in vain without him realizing
**First: I do not know what is the doubt that was thrown in the face of the sun here to extinguish its light. It is the direction of the Prophet, may God bless him and grant him peace, to his companions, teaching them that it is not permissible for Muslims to curse or fight each other. Therefore, was it required of the Messenger - in order to please the deceiver - to order the cursing and killing of Muslims? There is no power or strength except with God.
Second: This doubt and others prove that the deceiver is one of two things:
Either he does not know what he is saying.
Or he does not respect the intelligence of the reader, and this indicates the superficiality of his thinking.
**