Umar reported, "I heard Hisham bin Hakeem reciting Surah al-Furqan during the lifetime of the Messenger of Allah ﷺ. I listened closely to his recitation and found that he was reciting it according to many letters that the Messenger of Allah ﷺ had not taught me. I nearly leapt upon him during the prayer, but I held back until he gave the salam. As soon as he finished, I seized him by his cloak and said, 'Who taught you to recite this surah I just heard you reciting?'He replied, 'The Messenger of Allah ﷺ taught it to me.'I said, 'You are lying. By Allah, it was the Messenger of Allah ﷺ himself who taught me this very surah I heard you reciting.'So I led him by force to the Messenger of Allah ﷺ and said, 'Messenger of Allah, I heard this man reciting Surah al-Furqan with letters you did not teach me, while you yourself taught me Surah al-Furqan.'The Messenger of Allah ﷺ said, 'Release him, Umar. Recite, Hisham.'So Hisham recited it to him in the manner I had heard him recite.The Messenger of Allah ﷺ said, 'Thus it was revealed.'Then the Messenger of Allah ﷺ said, 'Recite, Umar.'So I recited it in the manner he had taught me.The Messenger of Allah ﷺ said, 'Thus it was revealed.' Then he said, 'This Quran was revealed in seven letters, so recite from it whatever is easy.'"
أخبرنا يونس بن عبد الأعلى قال حدثنا ابن وهب قال أخبرني يونس عن ابن شهاب قال أخبرني عروة بن الزبير أن المسور بن مخرمة وعبد الرحمن بن عبد القاري أخبراه أنهما سمعا
سمعت هشام بن حكيم يقرأ سورة الفرقان في حياة رسول الله ﷺ فاستمعت لقراءته فإذا هو يقرؤها على حروف كثيرة لم يقرئنيها رسول الله ﷺ فكدت أساوره في الصلاة فتصبرت حتى سلم فلما سلم لببته بردائه فقلت من أقرأك هذه السورة التي سمعتك تقرؤها فقال أقرأنيها رسول الله ﷺ فقلت كذبت فوالله إن رسول الله ﷺ هو أقرأني هذه السورة التي سمعتك تقرؤها فانطلقت به أقوده إلى رسول الله ﷺ فقلت يا رسول الله إني سمعت هذا يقرأ سورة الفرقان على حروف لم تقرئنيها وأنت أقرأتني سورة الفرقان فقال رسول الله ﷺ أرسله يا عمر اقرأ يا هشام فقرأ عليه القراءة التي سمعته يقرؤها قال رسول الله ﷺ هكذا أنزلت ثم قال رسول الله ﷺ اقرأ يا عمر فقرأت القراءة التي أقرأني قال رسول الله ﷺ هكذا أنزلت ثم قال رسول الله ﷺ إن هذا القرآن أنزل على سبعة أحرف فاقرءوا ما تيسر منه
Muslim reported it, no. 271/818 (see the previous hadith, no. 937), from the hadith of Ibn Wahb, and Bukhari, Istitabat al-Murtaddin, chapter on what has been said about those who make interpretations, no. 6936, from the hadith of Yunus bin Yazid, with the same wording. It is also in Kubra, no. 1010.