Hadith: We used to pay it (Zakat al-Fitr) as one Sā‘ of food, or one Sā‘ of barley, or one Sā‘ of dry crumbled milk, or one Sā‘ of raisins

عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ رضي الله عنه قَالَ:

كُنَّا نُخْرِجُ إِذْ كَانَ فِينَا رَسُولُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ زَكَاةَ الْفِطْرِ، عَنْ كُلِّ صَغِيرٍ وَكَبِيرٍ، حُرٍّ أَوْ مَمْلُوكٍ، صَاعًا مِنْ طَعَامٍ، أَوْ صَاعًا مِنْ أَقِطٍ، أَوْ صَاعًا مِنْ شَعِيرٍ، أَوْ صَاعًا مِنْ تَمْرٍ، أَوْ صَاعًا مِنْ زَبِيبٍ، فَلَمْ نَزَلْ نُخْرِجُهُ حَتَّى قَدِمَ عَلَيْنَا مُعَاوِيَةُ بْنُ أَبِي سُفْيَانَ حَاجًّا، أَوْ مُعْتَمِرًا فَكَلَّمَ النَّاسَ عَلَى الْمِنْبَرِ، فَكَانَ فِيمَا كَلَّمَ بِهِ النَّاسَ أَنْ قَالَ: إِنِّي أَرَى أَنَّ مُدَّيْنِ مِنْ سَمْرَاءِ الشَّامِ، تَعْدِلُ صَاعًا مِنْ تَمْرٍ، فَأَخَذَ النَّاسُ بِذَلِكَ، قَالَ أَبُو سَعِيدٍ: فَأَمَّا أَنَا فَلَا أَزَالُ أُخْرِجُهُ كَمَا كُنْتُ أُخْرِجُهُ، أَبَدًا مَا عِشْتُ.
[صحيح] - [متفق عليه]

Abu Sa‘īd al-Khudri (may Allah be pleased with him) reported: At the time of the Messenger of Allah (may Allah's peace and blessings be upon him) we used to pay it (Zakat al-Fitr) as one Sā‘ of food, or one Sā‘ of barley, or one Sā‘ of dry crumbled milk, or one Sā‘ of raisins. When Mu‘āwiyah came (during his rule) and the Syrian wheat became available, he said: "I see that one Mudd (quarter of a Sā‘) of this is equivalent to two Mudds (of other kinds of grains)." Abu Sa‘īd said: "As for me, I still pay it as I used to pay it during the Prophet's lifetime."
Sahih/Authentic. - [Al-Bukhari and Muslim]

Explanation

Abu Sa‘īd (may Allah be pleased with him) tells us that during the lifetime of the Messenger of Allah (may Allah’s peace and blessings be upon him) people used to pay Zakat al-Fitr as a Sā‘ of food. When Mu‘āwiyah (may Allah be pleased with him) arrived in Madīnah during his rule, he said: "c2">“I see that half a Sā‘ of the Syrian wheat is equivalent to one Sā‘ of anything else”. It was Ijtihād on his side that was not based on a Shariah text. His opinion was based on the fact that this kind of wheat was more expensive and of a higher quality than the dates, barley and other types of food. So people started to apply this. As for Abu Sa‘īd (may Allah be pleased with him), he disapproved of this opinion and committed himself to paying one Sā‘ of any type of food, just as he used to pay it during the lifetime of the Prophet (may Allah's peace and blessings be upon him) preferring to adhere to the prophetic tradition, and in order for the charity to achieve the desired sufficiency for people. It should be noted that the Sā‘ now equals approximately three kilograms.