A hadith and a commentary.
Jabir Ibn Sulaym came to the Prophet, peace and blessings of Allah be upon him.
He said to him,
"Give me a command, O Messenger of Allah."
Meaning, "Advise me."
So the Prophet, peace be upon him, said to him,
"Do not revile anyone."
Jabir, may Allah be pleased with him, said,
"I never reviled a free man or a slave after that,"
"nor a camel, nor a sheep."
The commentary:
Reviling is an act of disobedience to Allah and His Messenger, peace be upon him.
Therefore, avoid it—may Allah have mercy on you—and condemn it.