ALLAH 
SAYS: “Those who slander and ridicule such of the believers as give freely to charity, as well as those who can but give according to their means, Allah will throw back their ridicule upon them; and they shall have a grievous chastisement.” [1].
SAYS: “Those who slander and ridicule such of the believers as give freely to charity, as well as those who can but give according to their means, Allah will throw back their ridicule upon them; and they shall have a grievous chastisement.” [1].
He also says: “O believers, let not any group of you laugh at others, who may be better than them. Nor let some women ridicule others, who may be better than them. And do not defame or be sarcastic to each other, or call each other by [offensive] nicknames. Evil is a name connoting wickedness [used of anyone] after becoming a believer; and those who do not repent are wrongdoers.” [2].
also says: “O believers, let not any group of you laugh at others, who may be better than them. Nor let some women ridicule others, who may be better than them. And do not defame or be sarcastic to each other, or call each other by [offensive] nicknames. Evil is a name connoting wickedness [used of anyone] after becoming a believer; and those who do not repent are wrongdoers.” [2].
He says: “Woe to every scandalmonger and backbiter.” [3].
says: “Woe to every scandalmonger and backbiter.” [3].
As for the ṣaḥīḥ hadiths on this subject, they are too many to enumerate, and the consensus of the Ummah is that this is something that it is forbidden to do. And Allah knows best.
We relate in the Ṣaḥīḥ of Muslim that Abū Hurayrah 
narrated that the Messenger of Allah 
said: “Do not envy one another, do not bid up prices in order to cheat one another, do not hate one another, do not turn your backs on one another, and do not encroach upon each other’s trade. Be brothers, O slaves of Allah. The Muslim is the Muslim’s brother: he does not oppress him, he does not abandon him in his hour of need, and he does not belittle him. Taqwā is here”—and he pointed thrice to his heart. “It is sufficient evil for a man to belittle his Muslim brother. All of a Muslim is sacrosanct to a Muslim: his blood, his wealth and his honour.” [4].
narrated that the Messenger of Allah said: “Do not envy one another, do not bid up prices in order to cheat one another, do not hate one another, do not turn your backs on one another, and do not encroach upon each other’s trade. Be brothers, O slaves of Allah. The Muslim is the Muslim’s brother: he does not oppress him, he does not abandon him in his hour of need, and he does not belittle him. Taqwā is here”—and he pointed thrice to his heart. “It is sufficient evil for a man to belittle his Muslim brother. All of a Muslim is sacrosanct to a Muslim: his blood, his wealth and his honour.” [4].I say: “How beneficial and how abundantly valuable is this hadith for those who contemplate!”
We relate in the Ṣaḥīḥ of Muslim that Ibn Mas‘ūd reported that the Messenger of Allah said: “No one who has in his heart an atom’s weight of pride will enter Paradise.” Someone said: “But a man likes his clothes to look good and his shoes to look good.” He replied: “Allah is beautiful and He loves beauty. Pride is to regard the truth as false and to belittle people.” [5].
reported that the Messenger of Allah said: “No one who has in his heart an atom’s weight of pride will enter Paradise.” Someone said: “But a man likes his clothes to look good and his shoes to look good.” He replied: “Allah is beautiful and He loves beauty. Pride is to regard the truth as false and to belittle people.” [5].I say that baṭaru-l-ḥaqq, ‘to regard the truth as false’, is written with a fatḥah on the bā’ and the ṭā’, and means to repel [truth] and declare it false. Ghamṭ, ‘belittle’, is written with a fatḥah on the ghayn, a sukūn on the mīm and a ṭā’ at the end, and is also narrated as ghamṣ; both have the same meaning, which is ‘to despise’.
References
[1] Qur’ān 9:79.
[2] Qur’ān 49:11.
[3] Qur’ān 104:1.
[4] Muslim (2564).
[5] Muslim (91), Abū Dāwūd (4091), and at-Tirmidhī (1999).