"I heard As-Sa'ib bin Yazid say: 'During the time of Messenger of Allah, the Sa' was equal to a Mudd and third of the Mudd you use today, and the Sa' of today has become large."' (Sahih) Abu 'Abdur-Rahman (An-Nasa'i) said: And Ziyad bin Ayyub narrated it to me.  

كَانَ الصَّاعُ عَلَى عَهْدِ رَسُولِ اللَّهِ ﷺ مُدًّا وَثُلُثًا بِمُدِّكُمُ الْيَوْمَ وَقَدْ زِيدَ فِيهِ قَالَ أَبُو عَبْدِ الرَّحْمَنِ وَحَدَّثَنِيهِ زِيَادُ بْنُ أَيُّوبَ  

"The measure (to be used) is the measure of the people of Al-Madinah, and the weight (to be used) is the weight of the people of Makkah."  

عَنِ النَّبِيِّ ﷺ قَالَ الْمِكْيَالُ مِكْيَالُ أَهْلِ الْمَدِينَةِ وَالْوَزْنُ وَزْنُ أَهْلِ مَكَّةَ