Here Imam an-Nawawi gathers the Prophet's warnings against insulting, cursing, and falsely accusing a fellow believer. The recurring idea is that the tongue carries real weight before Allah: to revile a Muslim is named fusuq, open disobedience, and a false accusation does not stick to its target but rebounds onto the one who threw it.
Read these hadith together and a pattern appears. The believer's honor is sacred, the one who starts an insult carries its sin, and even a person caught in a sin like drunkenness must not be humiliated or have curses piled on him. The lane is mercy and self-restraint, not contempt.
Hadith 1559
Ibn Mas'ud (May Allah be pleased with him) reported:
وعن ابن مسعود رضي الله عنه قال: قال رسول الله صلى الله عليه وسلم : "سباب المسلم فسوق، وقتاله كفر" ((متفق عليه)).
The Messenger of Allah (ﷺ) said, "Reviling a Muslim is Fusuq (disobedience of Allah) and killing him is (tantamount to) disbelief." [Al-Bukhari and Muslim].
In plain words
Insulting a fellow Muslim is named here as open disobedience to Allah, and killing him is graver still. The hadith warns how seriously Islam treats the believer's life and honour.
Reference : Riyad as-Salihin 1559 In-book reference : Book 17, Hadith 49
Hadith 1560
Abu Dharr (May Allah be pleased with him) reported:
وعن أبي ذر رضي الله عنه أنه سمع رسول الله صلى الله عليه وسلم يقول: "لا يرمي رجل رجلا بالفسق أو الكفر، إلا ارتدت عليه، إن لم يكن صاحبه كذلك" ((رواه البخاري)).
I heard the Messenger of Allah (ﷺ) saying, "When any Muslim accuses another Muslim of sin or of disbelief, the reproach rebounds upon the one who utters it, if the other person is not deserving of it." [Al- Bukhari].
In plain words
If you accuse someone of sin or disbelief and the charge is untrue, the blame circles back onto you. A false accusation harms the one who throws it, not the innocent target.
Reference : Riyad as-Salihin 1560 In-book reference : Book 17, Hadith 50
Hadith 1561
Abu Hurairah (May Allah be pleased with him) said:
وعن أبي هريرة رضي الله عنه أن رسول الله صلى الله عليه وسلم قال: "المتسابان ما قالا فعلى البادي منهما حتى يعتدي المظلوم" ((رواه مسلم)).
The Messenger of Allah (ﷺ) said, "When two persons indulge in abusing each other, the beginner will be the sinner so long as the oppressed does not transgress the limits." [Muslim].
In plain words
When two people trade insults, the one who started it carries the sin, as long as the wronged person does not go too far in answering back. Beginning the abuse is what is condemned.
Reference : Riyad as-Salihin 1561 In-book reference : Book 17, Hadith 51
Hadith 1562
Abu Hurairah (May Allah be pleased with him) said:
وعنه قال: أتي النبي صلى الله عليه وسلم برجل قد شرب قال: "اضربوه" قال أبو هريرة: فمنا الضارب بيده، والضارب بنعله، والضارب بثوبه. فلما انصرف، قال بعض القوم: أخزاك الله، قال: "لا تقولوا هذا، لا تُعينوا عليه الشيطان" ((رواه البخاري)).
A drunkard was brought to the Prophet (ﷺ). He said, "Give him a beating." Then some beat him with their hands, some with their shoes, and some with (a folded) piece of cloth. When he left, someone said to him: "May Allah disgrace you!" The Prophet (ﷺ) said, "Do not help Satan overcome him by uttering such words." [Al- Bukhari].
In plain words
Even when a person is being punished for a wrong, the Prophet (peace be upon him) stopped others from cursing him. Piling on contempt only helps Satan; mercy and restraint are the better way.
Reference : Riyad as-Salihin 1562 In-book reference : Book 17, Hadith 52
Hadith 1563
Abu Hurairah (May Allah be pleased with him) said:
وعنه قال: سمعت رسول الله صلى الله عليه وسلم يقول: "من قذف مملوكه بالزنا يقام عليه الحد يوم القيامة، إلا أن يكون كما قال" ((متفق عليه)).
I heard the Messenger of Allah (ﷺ) saying, "He who accuses his slave of Zina will receive the punishment (Hadd) of slander on the Day of Resurrection, unless the accusation of Zina was true." [Al- Bukhari and Muslim].
In plain words
Falsely accusing someone of unlawful sex carries a heavy penalty on the Day of Resurrection. This shows how serious a slander against another person's chastity truly is.
Reference : Riyad as-Salihin 1563 In-book reference : Book 17, Hadith 53