جامع الترمذي

Abu Sa'eed Al-Khudri narrated: "We would give Zakat Al-Fitr - when the Messenger of Allah (ﷺ) was among us - as a Sa of food, or a Sa of barely, or a Sa of dried dates, or a Sa of raisins, or a Sa of cheese. So we did not stop paying it (like that) until Mu'awiyah arrived in Al-Madinah and talked (about it). Among the things he addressed the people with, he said: 'I see that two Mudd of the wheat of Ash-Sham are equal to a Sa of dried dates.' So the people followed that." Abu Sa'eed said: "I will not stop giving it in the manner that I had been giving it."