"Give Zakah of your fast." The people looked at one another, so he said: "Whoever is here from the people of Al-Madinah, get up and teach your brothers, for they do lnot know that this Zakah was enjoined by the Messenger of Allah upon every male and female, free and slave, a Sa' of barley or dates, or half a Sa' of wheat. "So they got up. (Da'if) Hisham contradicted him, he said: "From Muhammad bin Sirin."  

مَنْ هَا هُنَا مِنْ أَهْلِ الْمَدِينَةِ قُومُوا فَعَلِّمُوا إِخْوَانَكُمْ فَإِنَّهُمْ لاَ يَعْلَمُونَ إِنَّ هَذِهِ الزَّكَاةَ فَرَضَهَا رَسُولُ اللَّهِ ﷺ عَلَى كُلِّ ذَكَرٍ وَأُنْثَى حُرٍّ وَمَمْلُوكٍ صَاعًا مِنْ شَعِيرٍ أَوْ تَمْرٍ أَوْ نِصْفَ صَاعٍ مِنْ قَمْحٍ فَقَامُوا خَالَفَهُ هِشَامٌ فَقَالَ عَنْ مُحَمَّدِ بْنِ سِيرِينَ  

Ibn 'Abbas said concerning Sadaqatul-Fitr. "A Sa' of wheat, or a Sa' of dates, or Sa of barley, or a Sa' of rye." (Sahih Mawquf)  

صَاعًا مِنْ بُرٍّ أَوْ صَاعًا مِنْ تَمْرٍ أَوْ صَاعًا مِنْ شَعِيرٍ أَوْ صَاعًا مِنْ سُلْتٍ  

I heard Ibn 'Abbas deliver a Khutbah from your Minbar - meaning the Minbar in Al-Basrah - saying: 'Sadaqatul Fitr is a Sa' of food." (Sahih) Abu 'Abdur-Rahman (An-Nasa'i) said: This is the most reliable of the three.  

أَبُو عَبْدِ الرَّحْمَنِ هَذَا أَثْبَتُ الثَّلاَثَةِ