Sahih Bukhari
Obligatory Charity Tax After Ramadaan (Zakat ul Fitr)
Volume: 002 / Book Number: 025 / Hadith Number: 586
Narrated Abu Said Al-Khudri:
In the life-time of Allah's Apostle , we used to give one Sa' of food (edible things) as Sadaqat-ul-Fit,r (to the poor). Our food used to be either of barley, raisins (dried grapes), cottage cheese or dates.