How are credit cards (MasterCard or Visa) handled in the sale of gold and silver, given that these cards delay the deposit of the amount into the store's account by two or three days, which may conflict with the condition of immediate possession in the sale of gold for gold and silver for silver, or when their types differ?

If the Mastercard is covered, there is no harm in using it to pay for gold, as it functions as a constructive قبض (possession). The delay in crediting the amount to the account due to technical or administrative reasons beyond the control of the transacting parties does not affect the transaction. The banking entry is considered a constructive قبض, as it entails the beneficiary's ownership of the amount credited in the bank's records from the date of entry, and the money leaves the possession of its original owner to the other party. The delay in the banking entry is excused within the commonly accepted period during which the beneficiary can actually receive the funds, provided that the beneficiary does not dispose of the currency during the excused period until the effect of the banking entry is realized by the possibility of actual delivery.