Abdullah bin Umar (may Allah be pleased with them both) says that the Messenger of Allah (peace and blessings be upon him) prescribed sadaqat al-fitr of Ramadan: "Upon every soul among the Muslims, whether slave or free, man or woman, young or old: a sa' of dates or barley."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7689