"... As if they were uprooted stems of date-palms. Then, how (terrible) was My Torment and My Warnings?" (V.54: 20, 21)
Abu 'Is-haq
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'.
Reference
Sahih al-Bukhari 4871
In-book reference
Book 65, Hadith 392
USC-MSA web (English)
Vol. 6, Book 60, Hadith 394
Arabic Text
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.