"Give Zakah of your fast." The people started looking at one another. So he said: "Whoever is here of the people of Al-Madinah, get up and teach your brothers, for they do not know that the Messenger of Allah has enjoined Salaqatul Fitr upon young and old, free and slave, male and female; half a Sa' of wheat or a Sa' of dates or barely." Al_Hasan said: 'If Allah has given you more, then give more generously of wheat or something else."' (Using translation from Nasāʾī 2515)  

أَدُّوا زَكَاةَ صَوْمِكُمْ فَجَعَلَ النَّاسُ يَنْظُرُ بَعْضُهُمْ إِلَى بَعْضٍ فَقَالَ مَنْ هَاهُنَا مِنْ أَهْلِ الْمَدِينَةِ؟ قُومُوا إِلَى إِخْوَانِكُمْ فَعَلِّمُوهُمْ فَإِنَّهُمْ لَا يَعْلَمُونَ أَنَّ رَسُولَ اللهِ ﷺ «فَرَضَ صَدَقَةَ الْفِطْرِ عَلَى الصَّغِيرِ وَالْكَبِيرِ وَالْحُرِّ وَالْعَبْدِ وَالذَّكَرِ وَالْأُنْثَى نِصْفَ صَاعِ بُرٍّ أَوْ صَاعًا مِنْ تَمْرٍ أَوْ شَعِيرٍ» قَالَ الْحَسَنُ فَقَالَ عَلِيٌّ أَمَّا إِذَا أَوْسَعَ اللهُ عَلَيْكُمْ فَأَوْسِعُوا اجْعَلُوا صَاعًا مِنْ بُرٍّ أَوْ غَيْرِهِ