One prerequisite for an acceptable form of speech in Islam is that it must not give rise to incitement, communal strife, religious misinformation or spread of immorality. A proof that may be used in this regard is found the verse where Allah declares: "Indeed, those who like that immorality should be spread [or publicized] among those who have believed will have a painful punishment in this world and the Hereafter." [24:19] Thus, any act or verbal expression that involves deliberate intention to spread immorality among Muslims merits the punishment mentioned in the verse. This verse is also a proof against spreading malicious and unfounded rumors.
The Quran instructs to stay away from strife (fitan), commanding "And fear a trial (fitnah) which will not strike those who have wronged among you exclusively, and know that Allah is severe in penalty." Commenting on the above verse, Ibn ‘Abbas stated, "Allah instructed the believers not to approve immorality amongst themselves lest they should be included in the punishment." The companions of the Prophet were also cautious not to get involved in fitan and avoided asking about misconceptions. For instance, during the time of ‘Umar Ibn Al-Khattab, there was a man by the name of Ṣabigh who used to publicly enquire about misconceptions. So, ‘Umar summoned the man and punished him with a discretionary penalty.
Dictionaries record various meanings of fitnah, including temptation, trial, misguidance, enticement, fascination, commotion, sedition, affliction, torture, and strife. In the juristic Islamic literature, fitnah is tackled under various topics as per each of these definitions. However, the discussion of fitnah in this article is limited to seditious speech that gives rise to social or sectarian strife. As a matter of fact, speech may be phrased or delivered in a manner that evokes sectarian strife that in turn gives rise to discord and division within the society. It should be noted that Islam guarantees the non-Muslim subjects living under an Islamic state fair citizenship rights, and hence an act that violates their rights or incites aggression against them is criminalized. This fact is emphasized by the Prophet's hadith where he says, "Whoever killed a Mmu‘āhad (a person who is granted the pledge of protection by the Muslims) shall not smell the fragrance of Paradise though its fragrance can be smelt at a distance of forty years (of traveling).”
 Since fitnah-triggering speech is derogatory and seditious in essence, it is a penalized offence under the Sharia. Its penalty spans two cases. In the first case, it overlaps with sabb (insult) which is punishable by ta‘zi̅r. In the second case, it overlaps with incitement (tahri̅d), where the inciter is considered an indirect perpetrator of the crime and is to be punished under ta ‘zi̅r as well in proportion to the crime caused by his incitement.
Fitnah speech, in its political and social sense, is considered an abuse of freedom of expression. It threatens the security and stability of communities and gives rise to dissention among people and extremist reactions, whereas the Sharia emphasizes the promotion of solidarity within the community. This is mainly the reason why such a form of expression is prohibited and juridically criminalized under the Sharia.