Sarcasm is to imitate people’s words, deeds, or gestures so as to degrade or mock at them. Because such deeds of sarcasm create enmity, malice, and spoiling of the social relations, Islam has forbidden them. It is quite strange for one to mimic, degrade, or find fault with a believer sarcastically since every individual, except the Sinless1, must have some defects. Besides, every man may become the target of sarcasm and mimicry.
“Believers, let not a group of you mock another. Perhaps they are better than you. Let not women mock each other; perhaps one is better than the other. Let not one of you find faults in another nor let anyone of you defame another. How terrible is the defamation after having true faith. Those who do not repent are certainly unjust (49:11).”
“The sinners had been laughing at the believers. When passing by them, they would wink at one another and, on returning to their people, boast about what they had done. On seeing the believers, they would say, "These people have gone astray" (83:29-32).”
The Prophet (S) said: “Do not inspect the flaws of the believers. Allah will surely inspect the flaws of him who inspects the believers’ flaws. Allah will surely uncover the flaws of him whom He inspects, even if he hides himself in the middle of his house2.”
Imam as-Sadiq (a) said: “For him who mimics a believer for the purpose of disgracing him, abusing his personality, and making people disrespect him, Allah will dismiss him from His custody to the Shaitan’s, who, too, will not accept him3.”
It is related that, “Allah hides His disciples among His servants; hence, you should not disregard any of the servants of Allah, for it happens that he is one of the disciples of Allah while you do not know his reality.”