Is the lunar year (hawl) required for the rent of real estate? And what is the nisab (minimum threshold) for paper currency?

The questioner : He asks: Is it obligatory for the zakah on the rent of real estate that the lunar year (hawl) must pass over it, or should I pay zakah on it when I receive that rent, even if the lunar year has not passed? And what is the nisab for paper currency in riyals?

The Shaykh : The scholars (may Allah have mercy on them) differed regarding the wage. Some of them said that the wage is like the fruit. The wage is like the fruit. It does not have a lunar year of possession. Do you know what fruit is? The fruit of the date palm. The fruit of the date palm does not have a lunar year of possession. When its right is given on the day of its harvest, he holds that a person should pay zakah on the wage as soon as he receives it, even if only three months have passed.
And this is the choice of Shaykh al-Islam Ibn Taymiyyah (may Allah have mercy on him). He says: Because the common factor between the fruit and the rent is that all of it is a gain in kind. The fruit is the gain of a tree, and this is the gain of a building or land.
And this opinion is good and involves caution. And some of the scholars say that zakah is not obligatory on the rent unless the hawl is completed from the contract. For example, if the contract was made in Muharram and the rent was delivered in Muharram of the second year, then zakah becomes obligatory. And if the rent was delivered in the middle of the year in which the contract was completed, and the owner of the real estate spent it, and the hawl was not completed for him, then there is no zakah on it for him, because one of the conditions of zakah is the completion of the hawl. But what Shaykh al-Islam (may Allah have mercy on him) held is more cautious, more purifying for the conscience, and closer to qiyas (analogical reasoning).
As for the nisab of silver in riyals, this is asked about by those who engage in exchanging some currency for other currency. He goes to the man and says to him: If I have fifty-six Saudi riyals of silver, how much is that worth in paper? Whatever it is worth is the nisab, because the nisab of silver is fifty-six Saudi riyals of silver, and this is known to the dealers. It may be worth, for example, ten paper riyals, or it may be worth five, or it may be worth less, or it may be worth more. Yes. If we estimate, for example, that the Saudi silver riyal is worth ten paper riyals, how much would the nisab of paper be? It would be five hundred and sixty. Yes.