Fiqh-us-Sunnah Volume 3, Zakaat and Fasting, Fiqh 3.073A.

The jurists agree that unbelievers and atheists are not to be given zakah. In the hadith which says: “Zakah is taken from the rich and given back to the poor,” “the rich” refers to rich Muslims while “the poor” indicates poor Muslims. Ibn al-Munzhir said that all scholars agree that the free non-muslim subject (zhimmi) is not entitled to zakah. Exceptions to the rule are those people whose hearts are leaning toward Islam. However, it is permissible to give a zhimmi from the non-obligatory charity (tatawwu’). Alluding to the characteristics of the believers, the Qur’an says: “And for His love, they feed the indigent, orphan, and captive” (ad-Dahr: 8.. This is also supported by the following hadith: “Be kind to your mother.” The woman in this case was an unbeliever.