Alms Tax: Intention in Giving Zakat
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 1971
A person must give zakat with the intention of qurbah, i.e. in humility to Allah the Exalted. If he gives zakat without the intention of qurbah, it is sufficient [in the sense that he will be deemed as having given the zakat that was obligatory for him], although he will have sinned. Furthermore, he must specify in his intention whether what he is giving is zakat on property or zakāt al‑fiṭrah.[1] In fact, if, for example, zakat on wheat and barley is obligatory for him and he wants to pay a sum of money equal to the value of the zakat on them, he must specify whether he is giving zakat that is due on the wheat or barley.
-Ayatullah Sistani, Practical Laws of Islam, Alms Tax (Zakat)
The rules concerning zakāt al‑fiṭrah are mentioned in Ruling 2003 and onwards.