“And complete Hajj and ‘umrah for Allah,”

even if the person undertaking them does so voluntarily. Scholars have differed over whether other acts of worship must likewise be completed. Allah, glorified be He, has not made fulfilling an oath obligatory, because the person swearing it intends to urge or restrain action, not to draw closer to Allah Most High.

A vow, however, is generally expressed conditionally, making an obligation contingent upon something else, as when someone says, “If Allah cures my sick relative, I shall be obliged to free a slave.” An oath, on the other hand, generally takes the form of swearing, as when someone says, “By Allah, I shall certainly do such-and-such.” Swearing and a conditional undertaking may also be combined, as in His words:

“Among them are those who made a covenant with Allah: ‘If He gives us of His bounty, we will surely give in charity and be among the righteous.’”

“But when He gave them of His bounty, they withheld it and turned away in aversion.”

“So He caused hypocrisy to persist in their hearts until the Day they meet Him, because they broke their promise to Allah and because they used to lie.”

For this reason, jurists discuss one of these two forms under the heading “Chapter on Making Matters Conditional,” covering such matters as conditional divorce, manumission, vows, and the like. They discuss the other under “Chapter on General Rules of Oaths,” covering matters common to oaths by Allah, divorce, manumission, zihār, declarations of unlawfulness, and the like. The questions addressed in these two chapters overlap. Thus, some jurists discuss the general rules of oaths together with conditional declarations, while others discuss them in the “Chapter on Oaths.”

What is negated in one form is affirmed in the other, and what comes first in one comes last in the other. Thus, if someone says, “If I do such-and-such, my wealth is unlawful to me,” or “my slave is free,” or “my wife is divorced,” or “my wealth is to be given in charity,” or “I am bound to perform such-and-such a number of Hajj pilgrimages,” or “to fast for a month,” or the like,