"The Messenger of Allah enjoined Zakah of Ramadan upon the free and the slave, male and female, a Sa[1] of dates or a Sa of barley, so the people considered that equivalent to half a Sa of wheat." (Using translation from Nasāʾī 2500)  

«فَرَضَ رَسُولُ اللهِ ﷺ زَكَاةَ رَمَضَانَ عَلَى الْحُرِّ وَالْعَبْدِ وَالذَّكَرِ وَالْأُنْثَى صَاعًا مِنْ تَمْرٍ أَوْ صَاعًا مِنْ شَعِيرٍ فَعَدَلَ النَّاسُ بِهِ نِصْفَ صَاعٍ بُرٍّ»