What does Islam say about lying?

"Scholars have discussed the reality of truthfulness, often addressing specific meanings. Abu Bakr al-Warraq said truthfulness has three parts: the truthfulness of monotheism, the truthfulness of obedience, and the truthfulness of knowledge. The truthfulness of monotheism is for the general believers, as Allah Almighty said, "And those who believe in Allah and His messengers — they are the Siddiqeen."

"The first type of honesty is honesty of the tongue, which involves conveying information accurately, whether about the past or the future, including fulfilling promises. It is essential for every person to guard their speech, speaking only with honesty. This is the most recognized and apparent form of honesty. A person who refrains from speaking contrary to reality is truthful, but this honesty has two perfections."

"A person who embodies honesty in all these aspects is known as a "Siddiq," an exemplar of truthfulness. These aspects of honesty are ranked, and anyone who holds a share in any aspect is considered truthful relative to that aspect. The first type of honesty is honesty of the tongue, which involves conveying information accurately, whether about the past or the future, including fulfilling promises."

"Abi Ya'qub al-Nahrujuri said, "Truthfulness is aligning with the truth both inwardly and outwardly." Thus, the equivalence of inward and outward is one type of truthfulness. The sixth level of truthfulness, which is the highest and rarest, is truthfulness in the stations of religion, such as truthfulness in fear, hope, reverence, asceticism, satisfaction, reliance, love, and all other matters."

"Behold: the worst of the tales men carry are the tales of lying. Behold: lying is never proper, neither in earnest nor in jest, nor that a man promise his child something and then not fulfil it. Behold: lying leads to wickedness, and wickedness leads to the Fire; and truthfulness leads to righteousness, and righteousness leads to Paradise. It is said of the truthful man: he spoke truth and did right; and it is said of the liar: he lied and did wrong. Muhammad told us that a man keeps speaking the truth until he is written down with God as most truthful, and keeps lying until he is written down with God as a great liar."

"and corrupts their deeds as it corrupted the tongue's words, until lying pervades his words, his deeds, and his states, and the corruption takes firm hold of him, and his malady drives him toward ruin — unless God reaches him with the remedy of truthfulness, which uproots that disease from its very root. For this reason the foundation of all the works of the hearts is truthfulness, while their opposites — ostentation, self-conceit, arrogance, boastfulness, vainglory, insolence, wantonness, incapacity, sloth, cowardice, and baseness, and the like — all have lying as their root."

"resolve — so that he is true to Him in his resolve and true in his action. God, exalted is He, said: "And when the matter is resolved upon, were they but true to God, it would be better for them." His happiness, then, lies in truthfulness of resolve and truthfulness of deed. Truthfulness of resolve is to gather it and make it firm, without wavering within it — rather, it becomes a resolve unmixed with hesitation or delay. And once his resolve is true, there remains upon him truthfulness of action,"

"Perhaps he used to speak about what did not concern him and be stingy with what did not enrich him. Guard your tongue against eight things. First, lying. Guard it from lying in seriousness and jest. Do not accustom your tongue to lying in jest, lest it leads to lying in seriousness. Lying is among the greatest sins. If you become known for it, your credibility and respect will falter, and disdain and contempt will greet you."

"him, said, truthfulness leads to righteousness and righteousness leads to paradise. A man continues to be truthful and strives to be truthful until he is recorded with Allah as a truthful person. And lying leads to wickedness and wickedness leads to hell. A man continues to lie and strives to lie until he is recorded with Allah as a liar. The Prophet, peace be upon him, also said, the sign of a hypocrite is three. Even if he prays and fasts and claims to be a Muslim, when he speaks he lies. When he makes a promise he breaks it. And when he is entrusted he betrays. He further stated, whoever possesses four traits is"

"This requires clarification of the lie that اللّٰه has judged upon the slanderer, declaring him a liar in His sight, even if his report corresponds to reality. Lying can mean two things: one is a report that does not correspond to reality, which can be intentional or accidental. Intentional lying is well-known, while accidental lying is like the case of أَبُو سَنَابِل بْن بَعْكَك in his erroneous fatwa regarding the waiting period of a woman whose husband has died."