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-muratala is not currency exchange (al-sarf) because it involves the same type of money (e.g., gold for gold, silver for silver, 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.