As for the “conditional formula,” it is fundamentally a verbal sentence, since conditional particles are normally followed only by a verb. The “oath formula,” however, may be verbal, as in “I swear by Allah,” or ta-llāhi (“By Allah”), or wa-llāhi (“By Allah”), and similar expressions. It may also be nominal, as in “By Allah’s life, I shall certainly do it,” and “What is lawful is forbidden to me: I shall certainly do it.”

This classification is not confined to oaths between a servant and Allah; it also applies to contracts between people. Sometimes these take a conditional form, consisting of a condition and its consequence, as when someone offers a reward: “Whoever returns my runaway slave shall receive such-and-such,” or declares in a competition: “Whoever wins shall receive such-and-such.” At other times, they take an unconditional form: either a declarative formula, such as “I have sold” and “I have given in marriage,” or a request, such as “Sell to me” and “Grant me a divorce in return for compensation.”

The third preliminary point—which reveals the underlying principle governing questions concerning oaths and similar matters—is that the conditional formula, also called the “condition-and-consequence formula,” falls into six types. The person swearing may intend only the fulfilment of the condition, only the occurrence of the consequence, or both. Alternatively, he may intend neither to occur, but seek only the non-fulfilment of the condition, only the non-occurrence of the consequence, or the absence of both.

The first type is exemplified by many forms of divorce in return for compensation, contracts of manumission by payment, devotional vows, reward undertakings, and similar arrangements. A man might say to his wife, “If you give me a thousand, you are divorced,” or “If you give me a thousand, I have granted you a divorce in return for compensation.” Or he might say to his slave, “If you pay a thousand, you are free”; or say, “If you return my runaway slave, you shall receive a thousand”; or say, “If Allah heals my sick loved one, or