Lying is the source of all sins and it is the shortest way to Hell. The Prophet, , said: “Beware of lying because lying leads to dissoluteness, and dissoluteness leads to Hell. A person keeps on telling lies until he is written before Allah as a liar.” [Al-Bukhari and Muslim]

There are several causes of lying and various signs that indicate it. There is no doubt that knowing such causes and signs is of great help in treatment because the first step in the treatment of any disease is knowing its causes and determining its symptoms in order to eliminate them. Al-Maawardi mentioned some of these reasons as follows:

•  When one tells a liar something, he cannot differentiate between what he tells him and what he made up.
• One can make a liar doubtful of his own words to the extent that he might take them back.
• If one argues with a liar about what he said, he would get confused and not be able to defend himself or refute what he says.
• Doubt and suspicion would be apparent on his face. Some wise men have said that faces are like mirrors that expose the secrets that people conceal.

There are various types of lying; be it lying in deeds, sayings or intentions. The first is lying in sayings. It means deliberately telling something that is not true or real. This type has different forms that vary in the degree of guilt. The gravest and worst type is telling lies about Allah the Exalted and/or His Messenger, . Allah The Almighty Says (what means): {And who is more unjust than one who invents about Allah a lie} [Quran 6:21]

• {And do not say about what your tongues assert of untruth, “This is lawful and this is unlawful,” to invent falsehood about Allah}[Quran 16:116]
• {Or have they other deities who have ordained for them a religion to which Allah has not consented? But if not for the decisive word, it would have been concluded between them. And indeed, the wrongdoers will have a painful punishment.}[Quran 42:21]

Moreover, the Prophet, , warned us against telling lies about him when he said: “Whoever tells a lie about me intentionally, let him settle in his seat in Hell.”[Saheeh Al-Jaami‘ As-Sagheer: 6519]

This type also includes inventing lies about the believers such as those who testify to falsehood do. The Prophet, , considered testifying to falsehood one of the grave major sins. Nowadays, we find that many people sell their religion and conscience and testify to falsehood, thereby squandering or failing to give people’s rights or making false accusations against them out of greed for a worldly reward or to gratify their thirst for revenge.

Another example is lying when joking in order to make others laugh. The Prophet, , said: “Woe to him who lies to make people laugh. Woe to him! Woe to him!”[Ahmad and Abu Daawood, At-Tirmithi - Hasan]

A believer cannot be a liar for faith and lying cannot be combined in one person. Hence, when the Prophet, , was asked if a believer could be a liar, he replied in the negative, in spite of the fact that he stated that a believer could be a miser or a coward. This is because lying is one of the signs of hypocrisy. The Prophet, , said: “There are three characteristics of a hypocrite: when he speaks he lies, when he makes a promise he breaks it and when he is trusted he betrays.”