Alms Tax: Liability of a Poor Person for Zakat Given Prematurely

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 1984

If a poor person knows that zakat has not become obligatory for someone and yet accepts something from him as zakat and it perishes while it is with him, he [the poor person] is responsible for it. However, when zakat becomes obligatory for the person, if the poor person has remained poor, the one on whom zakat is obligatory can count the thing he had given the poor person as zakat.

-Ayatullah Sistani, Practical Laws of Islam, Alms Tax (Zakat)