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كتاب التفسير
65  
Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh))
(2c)
"... As if they were uprooted stems of date-palms. Then, how (terrible) was My Torment and My Warnings?" (V.54: 20, 21)
(2م1)
Sahih al-Bukhari 4871

Narrated Abu 'Is-haq:

A man asked Al-Aswad, 'is it 'Fahal min-Muddakir' or'..Mudhdhakir?" Al Aswad replied, 'I have heard `Abdullah bin Masud reciting it, 'Fahal-min Muddakir'; I too, heard the Prophet (ﷺ) reciting it 'Fahal-min-Muddakir' with 'd'.

حَدَّثَنَا أَبُو نُعَيْمٍ، حَدَّثَنَا زُهَيْرٌ، عَنْ أَبِي إِسْحَاقَ، أَنَّهُ سَمِعَ رَجُلاً، سَأَلَ الأَسْوَدَ فَهَلْ مِنْ مُدَّكِرٍ أَوْ مُذَّكِرٍ فَقَالَ سَمِعْتُ عَبْدَ اللَّهِ يَقْرَؤُهَا ‏{‏فَهَلْ مِنْ مُدَّكِرٍ‏}‏ قَالَ وَسَمِعْتُ النَّبِيَّ صلى الله عليه وسلم يَقْرَؤُهَا ‏{‏فَهَلْ مِنْ مُدَّكِرٍ‏}‏ دَالاً‏.‏
Reference : Sahih al-Bukhari 4871
In-book reference : Book 65, Hadith 392
USC-MSA web (English) reference : Vol. 6, Book 60, Hadith 394
  (deprecated numbering scheme)