Al-Matalib al-'Aliyah 2731 — Prohibition of finding fault with people

It is narrated from Sayyiduna al-Nu'man bin Bashir (may Allah be pleased with him) that Sayyiduna Thabit bin Qays bin Shammas (may Allah be pleased with him) had missed one rak'ah of the Fajr prayer, so he stood up to complete it. Meanwhile the Prophet (peace and blessings be upon him) took his seat and the people gathered and sat around him (peace and blessings be upon him). When Thabit bin Qays (may Allah be pleased with him) had completed his prayer, he came to a man and said to him: "Make room for me," and he made room for him. Then he came to a second man and said to him: "Make room for me," and he too made room for him. Then he came to a third man and said: "Make room for me," but he replied: "There is ample room behind you; what need do you have to step over people's necks?" Thabit (may Allah be pleased with him) looked at his face and said in anger: "O son of so-and-so woman!" The Messenger of Allah (peace and blessings be upon him) heard this and asked: "Who is it that taunted this man about his mother just a little while ago?" The people remained silent. He (peace and blessings be upon him) asked again: "Who is it that just now taunted this person about his mother?" Then Thabit (may Allah be pleased with him) stood up and said: "O Messenger of Allah! I had missed a rak'ah, and there is some heaviness (deafness) in my ears, so I wished to sit near you, while the people were sitting in a circle around you." Then he related the whole incident and said: "I taunted him about his mother who lived in the Jahiliyyah (pre-Islamic era), and other women were better than her." At this the Messenger of Allah (peace and blessings be upon him) said: "O Thabit bin Qays! Raise your head and look at this gathering; among them are black, white and red people of every kind. Know that you have no superiority or virtue over any of them except through taqwa (God-consciousness) and piety."
The narrator states: After that incident I never taunted anyone.