The World Federation One Stop Fiqh

Ruling 2029

A person cannot give as fiṭrah half a ṣāʿ of one item, such as wheat, and half a ṣāʿ of another item, such as barley. In fact, even if he gives half a ṣāʿ with the intention of paying the value of the fiṭrah [as opposed to giving the quantity of the item], it is not sufficient.