The Nisab of Paper Currency

The Shaykh : The zakah of what is in the category of gold and silver: my intention is that the nisab of what is in the category of gold and silver is reached when it attains the nisab, either in gold or in silver. One looks at what is most beneficial for the recipients of zakah. If we calculate that the zakah of silver in Saudi currency is fifty-six riyals of silver, then look at the value of fifty-six riyals of silver in paper currency, and this becomes the nisab. If we ask those who deal in buying and selling gold, silver, and paper currency, and say to them, "What is the value of the Saudi riyal in silver according to paper currency?" and they say, "The value of the riyal is ten of paper currency," then what is the nisab? The nisab in silver is fifty-six riyals, and the value of the riyal in paper currency is ten; what is the total? Five hundred and sixty. If they say that the riyal of silver is equal to twenty of paper currency, it is one thousand and one hundred and twenty. If they say fifty-six, and that the riyal is equal to five hundred and eighty, multiply fifty-six by five. It is subject to increase and decrease according to the value of silver. If the value increases, the nisab changes; if it decreases, the nisab changes.