عَنْ أَبِي إِسْحَاقَ قَالَ رَأَيْتُ رَجُلًا سَأَلَ الْأَسْوَدَ بْنَ يَزِيدَ وَهُوَ يُعَلِّمُ الْقُرْآنَ فِي الْمَسْجِدِ فَقَالَ كَيْفَ نَقْرَأُ هَذَا الْحَرْفَ فَهَلْ مِنْ مُدَّكِرٍ [القمر: 15] أَذَالٌ أَمْ دَالٌ فَقَالَ لَا بَلْ دَالٌ ثُمَّ قَالَ سَمِعْتُ عَبْدَ اللَّهِ بْنَ مَسْعُودٍ رَضِيَ اللَّهُ عَنْهُ يَقُولُ سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ يَقْرَؤُهَا مُدَّكِرٍ دَالًا
Abu Ishaq says: I saw a man who asked Aswad bin Yazid, who used to teach the Qur'an in the mosque, and said: How should we recite this verse: {فَہَلْ مِنْ مُدَّکِرٍ} Is it with "dh" or "d"? He replied: No, it is with "d". I heard Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) say, he said: I heard the Messenger of Allah (peace and blessings be upon him) recite {مُدَّکِرٍ} with "d".