Asma bint Abi Bakr (may Allah be pleased with her) says that in the time of the Messenger of Allah (peace and blessings be upon him) they used to give zakah with the mudd by which the household measured their daily food, or with the sa' by which they measured their food; all the people of Madinah did so.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7716