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bayhaqi:7715Abū Isḥāq Ibrāhīm b. Muḥammad al-Armawī > Shāfiʿ b. Muḥammad > Abū Jaʿfar al-Ṭaḥāwī > al-Muzanī > al-Shāfiʿī > Yaḥyá b. Ḥassān > al-Layth b. Saʿd > ʿAqīl b. Khālid And ʿAbd al-Raḥman b. Khālid b. Musāfir > Ibn Shihāb > Saʿīd b. al-Musayyib > Rasūl Allāh ﷺ

[Machine] He obligated the payment of Zakat al-Fitr in a specific measure of wheat. Ash-Shafi'i said that the hadith of "muddayin" (specific measure) is a mistake, and the scholar said that it is as he said, and the established reports indicate that the measure of a "muddayin" was after the Messenger of Allah ﷺ. It was narrated that it is permissible to give half a saa' of barley as Sadaqat al-Fitr from Abu Bakr As-Siddiq, Uthman ibn Affan, Jabir ibn Abdullah, and Abu Hurairah. And in one of the two narrations, it was narrated from Ali and Ibn Abbas. Ibn al-Mundhir said that this is not confirmed from Abu Bakr and Uthman. The scholar said that it is disconnected from Abu Bakr and connected to Uthman, and Allah knows best. And there are reports that came from the Prophet ﷺ regarding a saa' of barley, and reports that came regarding half a saa', and none of that is correct. I have explained the reasons for each of them in detail in Al-Khilafiyat (the disagreements). And it was narrated in the hadith of Abu Sa'eed Al-Khudri and in the confirmed hadith from Ibn Umar that the t'adil (specific measure) of a muddayin is half a saa' of barley per saa' of barley, and it occurred after the Prophet ﷺ. And with Allah is the facilitation.  

البيهقي:٧٧١٥أَخْبَرَنَا أَبُو إِسْحَاقَ إِبْرَاهِيمُ بْنُ مُحَمَّدٍ الْأَرْمَوِيُّ أنبأ شَافِعُ بْنُ مُحَمَّدٍ أنبأ أَبُو جَعْفَرٍ الطَّحَاوِيُّ ثنا الْمُزَنِيُّ ثنا الشَّافِعِيُّ عَنْ يَحْيَى بْنِ حَسَّانَ عَنِ اللَّيْثِ بْنِ سَعْدٍ عَنْ عَقِيلِ بْنِ خَالِدٍ وَعَبْدِ الرَّحْمَنِ بْنِ خَالِدِ بْنِ مُسَافِرٍ عَنِ ابْنِ شِهَابٍ عَنْ سَعِيدِ بْنِ الْمُسَيِّبِ أَنَّ رَسُولَ اللهِ ﷺ

فَرَضَ زَكَاةَ الْفِطْرِ مُدَّيْنِ مِنْ حِنْطَةٍ قَالَ الشَّافِعِيُّ حَدِيثُ مُدَّيْنِ خَطَأٌ قَالَ الشَّيْخُ هُوَ كَمَا قَالَ فَالْأَخْبَارُ الثَّابِتَةُ تَدُلُّ عَلَى أَنَّ التَّعْدِيلَ بِمُدَّيْنِ كَانَ بَعْدَ رَسُولِ اللهِ ﷺ وَرُوِّينَا فِي جَوَازِ نِصْفِ صَاعٍ مِنْ بُرٍّ فِي صَدَقَةِ الْفِطْرِ عَنْ أَبِي بَكْرٍ الصِّدِّيقِ وَعُثْمَانَ بْنِ عَفَّانَ ؓ وَجَابِرِ بْنِ عَبْدِ اللهِ وَأَبِي هُرَيْرَةَ وَفِي إِحْدَى الرِّوَايَتَيْنِ عَنْ عَلِيٍّ وَابْنِ عَبَّاسٍ ؓ قَالَ ابْنُ الْمُنْذِرِ لَا يَثْبُتُ ذَلِكَ عَنْ أَبِي بَكْرٍ وَعُثْمَانَ ؓ قَالَ الشَّيْخُ هُوَ عَنْ أَبِي بَكْرٍ مُنْقَطِعٌ وَعَنْ عُثْمَانَ مَوْصُولٌ وَاللهُ أَعْلَمُ وَقَدْ وَرَدَتْ أَخْبَارٌ عَنِ النَّبِيِّ ﷺ فِي صَاعٍ مِنْ بُرٍّ وَوَرَدَتْ أَخْبَارٌ فِي نِصْفِ صَاعٍ وَلَا يَصِحُّ شَيْءٌ مِنْ ذَلِكَ قَدْ بَيَّنْتُ عِلَّةَ كُلِّ وَاحِدٍ مِنْهَا فِي الْخِلَافِيَّاتِ وَرُوِّينَا فِي حَدِيثِ أَبِي سَعِيدٍ الْخُدْرِيِّ وَفِي الْحَدِيثِ الثَّابِتِ عَنِ ابْنِ عُمَرَ أَنَّ تَعْدِيلَ مُدَّيْنِ مِنْ بُرٍّ وَهُوَ نِصْفُ صَاعٍ بِصَاعٍ مِنْ شَعِيرٍ وَقَعَ بَعْدَ النَّبِيِّ ﷺ وَبِاللهِ التَّوْفِيقُ