It is narrated from Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) recited this verse: "You have reached from me an excuse" [Surah al-Kahf: 76], reading "ladunni" with a doubled (shaddah) nun.
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 540