Know that lying, although impermissible in principle, is permissible in some cases with conditions that I have underlined in my book Al-Adhkār. In a nutshell, speech is a means to achieve purposes, so if a good purpose can be achieved without lying, then it is impermissible to resort to lying to achieve it. But, if lying is the only way to achieve it, then it is permissible to lie in this case. Also, if achieving that purpose is permissible, then lying is permissible, and if it is obligatory, then lying to achieve it is obligatory as well. For example, if a Muslim is hiding from an oppressor who wants to kill him, or he hides his property from someone who wants to usurp it, then someone is asked about him or about his property, it is obligatory to lie in order to keep them hidden. The more prudent procedure here is to resort to Tawriyah, which is to say something which has more than one meaning and intend a meaning different from what the listener is likely to understand. But if a person chooses not to use Tawriyah and says untrue words, it is not prohibited in these situations.
Scholars use as evidence of the permissibility of lying in these situations the Hadīth of Um Kulthūm (may Allah be pleased with her) who reported that she heard the Messenger of Allah (may Allah’s peace and blessings be upon him) say: “The liar is not the one who seeks reconciliation between people, conveying good (things) or saying good things.” [Narrated by Al-Bukhāri and Muslim]
A narration of Muslim of the same Hadīth has the following addition: Um Kulthūm said: “I did not hear him allowing people to lie except in three cases: war, reconciliation between people, and what a man says to his wife and a woman to her husband.”
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1) If someone does not tell the truth with the aim of reconciling people, he is not considered a liar.
2) Blameworthy lying is that which results in evil and harm. Permissible lying, however, is the one explained by the Islamic law and which brings about an interest and benefit that are permissible under the Shariah.