أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا حَمَّادٌ، عَنْ أَيُّوبَ، عَنْ أَبِي رَجَاءٍ، قَالَ سَمِعْتُ ابْنَ عَبَّاسٍ، يَخْطُبُ عَلَى مِنْبَرِكُمْ - يَعْنِي مِنْبَرَ الْبَصْرَةِ - يَقُولُصَدَقَةُ الْفِطْرِ صَاعٌ مِنْ طَعَامٍ ‏.‏قَالَ أَبُو عَبْدِ الرَّحْمَنِ هَذَا أَثْبَتُ الثَّلاَثَةِ ‏.‏

It was narrated that Abu Raja' said

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.