The sale (ba’i or bay’) in which a type of money (naqd) is exchanged for money of its genus based on weight (wazn). In this sense, al-muratalah is not currency exchange (al-sarf) because it involves the same type of money (e.g., gold for gold, silver for silver, dinar for dinar, dirham for dirham, etc), rather than two different types (e.g., gold for silver) as in al-sarf. Al-muratalah is similar to al-mubadalah in principle, i.e., both entail the exchange of the same type of money. However, al-mubadalah is based on count rather than weight.