Sunan an-Nasa'i 2504
سنن النسائي#2504SahihIt was narrated that Ibn 'Umar said:"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
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih Bukhari
In-book reference: 23:70