Mkhld bin Yazid al-Quraishi مخلد بن يزيد القرشي الحراني · The Book of Zakah

"The Messenger of Allah enjoined Zakatul-Fitr, a Sa' of dates or a Sa of barley, upon the free person and the slave, male and female, young and old, among the Muslims. He commanded that it be given before the people went out to the ('fd) prayer."