Sayyiduna Saabit Bin Qays  had weak hearing. For this reason, whenever he would be in the blessed gathering, the holy companions  would give him a position at the front. One day when
he came in the blessed court of the Beloved Rasool ,
the space had been filled up, but he  reached near the Holy Rasool
by moving people aside. Yet one person remained between him and the Holy Rasool  . Sayyiduna Saabit Bin Qays   started to move him but that person did not move at all from his position. Sayyiduna Saa bit Bin Qays   furiously asked him, ‘Who are you?’ The person replied that he was so-and-so person. Upon hearing this, Sayyiduna Saabit Bin Qays said scornfully, ‘Oh! So you are the son of so-and-so woman.’ On hearing these comments, the man embarrassed, he bowed his head and became extremely aggrieved. On this occasion, the Quranic Ayah mentioned ahead was revealed.
It has been reported by Sayyiduna Dahhaak that a few people of the tribe Bani Tameem dressed up in luxurious attire came in the court of the  Holy Rasool . When they saw the poor condition of Ashaab-us­Suffah, they made fun of them. This Ayah was revealed at that occasion.
(I’afseer Khaza’in-ul-‘Irfan, pp. 929; part 26, Surah Al-Hujurat, Ayah 11)
Sayyiduna Anas  has reported that one day, Sayyidatuna ‘Aaishah  called Umm-ul-Mu’mineen Sayyidatuna Safiyyah  a Jewess, who became extremely grieved at it. When the Rasool of Rahmah   came to know about it, he  expressed serious resentment towards Sayyidatuna ‘Aaishah ; and in order to please Sayyidatuna Safiyyah  he said to her, ‘You are among the progeny of a Nabi (Sayyiduna Haroon ) and there was a Nabi among your uncles too (Sayyiduna Musa) and you are also the wife of a Nabi, meaning you are my wife’. This Ayah was revealed on this occasion. (I’afseer As-Saawi, vol. 5, pp. 1494; part 26, Surah Al-Hujurat, Ayah 11)
Anyhow, this Ayah was revealed for one of the three aforementioned events, where Allah  strictly prohibited making mockery of any nation. This very Ayah is:

0 believers! Men must not ridicule other men, it’s likely that the ridiculed are better than the mockers, nor must the women ridicule other women, it’s likely that the ridiculed women may be better than the mockers; and do not taunt one another, nor give evil nicknames. What a bad name it is to be called an evildoer after being a Muslim. And whoever does not repent, it is they who are unjust.
[Kanz-ul-Iman (Translation of Quran)J (Part 2 6, Surah Al-Hujurat, Ayah 11)


 Read above glittering and guiding Ayahs of the Holy Quran carefully and learn a lesson from them. Nowadays, a sinful tradition is prevalent whereby those known by the titles of ‘Sayyid’, ‘Shaykh’ and ‘Pathan’ ridicule sincere and devout Muslims belonging to the tribes of butchers, barbers, weavers, vegetable seller etc. Furthermore, they even do not value the  religious scholars belonging to these castes and do not pay respect to them merely because of their race. They make fun of them in their gatherings,  laughing and making others laugh too. Not only common people exhibit misconduct with such tribes, but also sometimes scholars and spiritual Shay khs are found indulged in this misconduct. Even the people who learnt from the scholars of those communities ridicule  their teachers thinking of them as inferior
and mediocre merely due to community
based differences. By boasting upon their ”
own status and caste, they commit the
degradation and disgrace of others. How criminal these people are in the light of Holy Quran! Read following warnings and regulations that the Holy Quran has mentioned in this context:
l. No caste or community should ridicule another caste or community, as it is possible that the ones being ridiculed may be better than those ridiculing, in this world and in the Hereafter.
2. It is not permissible for the Muslims to taunt one another.
3. It is Haraam (prohibited) for the Muslims to use bad names for one another.
4. A person who does so is a transgressor, despite being Muslim.
5. A person who does not repent from such of his practices is an oppressor.
Sayyiduna Ibn ‘Abbas has mentioned that if a sinful Muslim repents from his sin, then to embarrass him about that sin is also prohibited. Similarly, it is also prohibited to call a Muslim a dog, donkey or a pig or calling a Muslim by such name or title that reveals a flaw in him or is offensive to him. All such forms of acts are also included in this prohibition. (Iafseer Khaza’in-ul-‘Irfan, pp. 930; part 26, Surah Al-Hujurat, Ayah 11)
Sayyiduna ‘Abdullah Bin Mas’ ood has said, ‘If I ridicule someone perceiving him as inferior, I am afraid that Allah may transform me into a dog.’ (Iafseer As-Saawi, vol. 5, pp. 1994; part 26, Surah Al-Hujurat, Ayah 11)