As-Sa'ib bin Yazid said, "The Sa' at the time of the Prophet ﷺ was equal to one Mudd plus one-third of a Mudd of your time, and then it was increased in the time of Caliph ʿUmar bin ʿAbdul ʿAziz."
كَانَ الصَّاعُ عَلَى عَهْدِ النَّبِيِّ ﷺ مُدًّا وَثُلُثًا بِمُدِّكُمُ الْيَوْمَ فَزِيدَ فِيهِ فِي زَمَنِ عُمَرَ بْنِ عَبْدِ الْعَزِيزِ
"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
[Machine] "He (Saib ibn Yazid) was the measurement during the time of the Messenger of Allah ﷺ , equaling one and a third of your measurement today. It increased during the time of Umar ibn Abdul Aziz. Saib said, 'I performed Hajj during the time of the Prophet ﷺ while I was still a young boy.'"
لِيَ السَّائِبُ بْنُ يَزِيدَ كَانَ الصَّاعُ عَلَى عَهْدِ رَسُولِ اللهِ ﷺ مُدًّا وَثُلُثًا بِمُدِّكُمُ الْيَوْمَ فَزِيدَ فِيهِ فِي زَمَنِ عُمَرَ بْنِ عَبْدِ الْعَزِيزِ قَالَ وَقَالَ السَّائِبُ «حُجَّ بِي فِي زَمَانِ النَّبِيِّ ﷺ وَأَنَا غُلَامٌ»
[Machine] The traveler said to me, "During the time of the Prophet Muhammad ﷺ, the measurement of a sa' was a certain amount, and one-third of that measurement is what you have today. It was increased during the time of Umar ibn Abdul Aziz." The traveler continued, "I performed Hajj along with the Prophet ﷺ when I was a young boy."
قَالَ لِي السَّائِبُ كَانَ الصَّاعُ عَلَى عَهْدِ رَسُولِ اللهِ ﷺ مُدًّا وَثُلُثَ مُدِّكُمُ الْيَوْمَ فَزِيدَ فِيهِ فِي زَمَنِ عُمَرَ بْنِ عَبْدِ الْعَزِيزِ قَالَ السَّائِبُ وَحُجَّ بِي فِي ثَقَلِ النَّبِيِّ ﷺ وَأَنَا غُلَامٌ