Riyad Us-Saliheen (Gardens of the Righteous)
Illegality of Swearing Falsely
1712. Ibn Mas`ud (May Allah be pleased with him) said: The Prophet (PBUH) said, "He who takes oath to acquire the property of a Muslim unjustly will meet Allah and He will be angry with him'' then he recited:
"Verily, those who purchase a small gain at the cost of Allah's Covenant and their oaths, they shall have no portion in the Hereafter. Neither will Allah speak to them nor look at them on the Day of Resurrection nor will He purify them, and they shall have a painful torment.'' (3:77)
[Al-Bukhari and Muslim].
1713. Abu Umamah Iyas bin Tha`labah Al-Harithi (May Allah be pleased with him) said: The Messenger of Allah (PBUH) said, "He who misappropriates the right of a Muslim by taking a false oath, Allah will condemn him to the fire of Hell and will forbid Jannah for him.'' A person asked: "O Messenger of Allah, even if it is something insignificant?'' He replied, "Yes, even if it is the twig of the Arak tree.''
1714. `Abdullah bin `Amr bin Al-As (May Allah be pleased with them) said: The Prophet (PBUH) said, "Of the major sins are: Associating anything in worship with Allah, disobedience to the parents, killing without justification and taking a false oath (intentionally).''
Another narration is: A bedouin came to the Prophet (PBUH) and asked him: "O Messenger of Allah, what are the cardinal sins?'' He (PBUH) replied, "Associating anything with Allah in worship.'' The man asked: "(What is) next?'' The Messenger of Allah (PBUH) replied, "Al-Yamin Al-Ghamus.'' He asked: "What do you mean by Al-Yamin Al-Ghamus?'' The Messenger of Allah (PBUH) replied, "Swearing falsely to usurp the property of a Muslim.''
Commentary: "Ghamus'' means to drown. A false oath drowns one in sin. For this reason, it is called Al-Yamin Al-Ghumus, the oath that drowns one in sin. Is it open to expiation? Some religious scholars believe that it is, while others think it is not, because in their opinion it is a lie which is employed to deprive somebody of his wealth and property. For this reason, they say that in such case one should beg pardon from Allah and arrange to restore the wealth and property to the victim. This seems to be the more appropriate course for it because mere repentance cannot remit this sin. It is necessary to rectify the wrong and compensate the victim.