عَنِ ابْنِ عَبَّاسٍ رَضِيَ اللَّهُ عَنْهُمَا عَنْ أُبَيِّ بْنِ كَعْبٍ رَضِيَ اللَّهُ عَنْهُ عَنِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ أَنَّهُ قَرَأَ {قَدْ بَلَغْتَ مِنْ لَدُنِّي عُذْرًا} [الكهف: 76] يُثَقِّلُهَا
It is narrated from Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) recited this verse as follows: {قَدْ بَلَّغْتَ مِن لَّدُنِّیْ عُذْرًا}, that is, he pronounced "Ladunni" with a shaddah (emphasis).