Abu Hudhayfah (may Allah have mercy on him) says that Sufyan (may Allah have mercy on him) narrated the hadith with the same chain, saying: "In the time of the Messenger of Allah (peace and blessings be upon him) we used to give one sa' of wheat, dates, barley, raisins or cheese (aqit)." When Amir Mu'awiyah (may Allah be pleased with him) came and the brown Syrian wheat (samra') arrived, the people considered it equal to two mudd of wheat.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7730