Book of Oaths and Vows
Chapter: Rulings Concerning Oaths

The term aymān is the plural of yamin. A yamin (oath) is an assertion of a ruling accompanied by the mention of something held in great veneration, uttered in a specific manner. It takes its name from the right hand because, when swearing, a person offers his right hand and strikes the right hand of his counterpart, as is done when concluding a covenant or contract.

The oath that requires an expiation is the one in which the swearer invokes the Name of Allah or one of His attributes—for example, saying: “By Allah,” or “By the Face of Allah,” or “By His greatness, majesty, grandeur, might, mercy,” or “By His covenant,” or “By His will,” or “By the Quran,” or “By the Mushaf.”

Swearing by anything other than Allah is forbidden and constitutes shirk, for the Messenger of Allah, peace and blessings be upon him, said: “Whoever must swear, let him swear by Allah or remain silent” (agreed upon). He also said: “Whoever swears by anything other than Allah has committed disbelief or shirk,” and: “He is not of us who swears by trustworthiness,” narrated by Abu Dawud.