Zakat al-Fitr is obligatory for every free, wealthy Muslim, whether young or old, male or female. It is obligatory but not a mandatory duty; because a mandatory duty is something that is established as necessary by a definitive proof, and the necessity of this type of zakat has not been established by definitive proof, but rather by evidence that has some ambiguity regarding its existence, which is the report of a single narrator. Ibn Umar (may Allah be pleased with him) reported: "Indeed, the Messenger of Allah (peace be upon him) made Zakat al-Fitr obligatory upon the people at the end of Ramadan, one sa' of dates or one sa' of barley for every free or enslaved male or female Muslim," in Sahih Muslim 2: 677, and Sahih al-Bukhari 2: 547. The meaning of obligatory here refers to the amount to be given for Fitr; because in the language, the term 'obligatory' refers to estimation. Allah, the Exalted, said: (So half of what you have made obligatory) Al-Baqarah: 237: meaning what you have estimated. Abdullah ibn Thalabah (may Allah be pleased with him) said that the Prophet (peace be upon him) said: "Give one sa' of wheat or barley between two people or one sa' of dates or one sa' of barley for every free person and slave, young and old," in Sunan al-Daraqutni 2: 150. Ibn Umar (may Allah be pleased with him) reported: "The Prophet (peace be upon him) commanded Zakat al-Fitr for every small and large person, free or enslaved, one sa' of barley or one sa' of dates, and people later adjusted it to a mudd of wheat," in Sahih Ibn Khuzaymah 4: 86, and Sahih Ibn Hibban 8: 94. Ibn Abbas (may Allah be pleased with him) reported: "Indeed, the Messenger of Allah (peace be upon him) made Zakat al-Fitr obligatory, half a sa' of wheat, or one sa' of barley, or one sa' of dates for the free and enslaved, male and female," in Musnad Ahmad 1: 351, and Sunan al-Daraqutni 2: 152. See also: Bada'i al-Sana'i 2: 69.