It was narrated that Abu Saeed Al-Khudri said: “At the time of the Messenger of Allah صلی اللہ علیہ وآلہ وسلم we used to give a ‘a’ of barley, or dates, or raisins, or cottage cheese, and we continued to do so until the time of Muawiyah, when he said: ‘I think that two Mudds of wheat from Ash-Sham are equivalent to a ‘a’ of barley.”(Sahih).