—that is, weight for weight, exactly equal, hand to hand. For example, if you took two mithqāls of 18-carat gold in exchange for one and a half mithqāls of 24-carat gold, the deal would be unlawful, because strict equivalence is required. Likewise, if you exchanged two mithqāls for two mithqāls of gold but delayed taking possession of one of the amounts, the transaction would still be impermissible, since both parties must take physical delivery in the very session in which the contract is concluded.

The same principle applies when gold is sold for the familiar paper currency: if someone buys gold from a merchant or a goldsmith, he may not leave until he has paid the full price, for these banknotes take the legal status of silver. Whenever gold is exchanged for silver, both sides must take immediate possession before parting, in keeping with the Prophet’s—peace and blessings be upon him—saying: “When these categories differ, sell as you wish, provided it is hand to hand.” (1)

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Question Twenty-One: What is the ruling on selling gold rings that are specifically