What is the ruling on selling silver riyals for paper riyals at a premium?

Scholars have differed on the ruling concerning selling banknotes for silver. Some have permitted it, arguing that paper is not silver, while others have prohibited it, stating that paper has taken the place of silver in transactions. The more cautious approach is to abstain from it, based on the Prophet's (peace and blessings be upon him) saying: "Leave that which makes you doubt for that which does not make you doubt," and "Whoever guards himself against doubtful matters, he has indeed protected his religion and his honor." It is better to sell silver for another type of commodity, such as gold, and then purchase banknotes with it, or to sell banknotes for gold and then purchase silver with it.