Hisham bin Hakeem reported,

...reciting Surah al-Furqan in a way different from how I recited it, and the Messenger of Allah ﷺ himself had taught me to recite it. I almost rushed at him, but I held back until he finished. Then I seized him by his cloak and brought him to the Messenger of Allah ﷺ.I said, "Messenger of Allah, I heard this man reciting Surah al-Furqan in a way different from how you taught me to recite it."The Messenger of Allah ﷺ said, "Let him go. Recite."So he recited the same recitation I had heard him reciting.The Messenger of Allah ﷺ said, "It was revealed this way."Then he said to me, "Recite."So I recited.He said, "It was revealed this way. Indeed, this Quran was revealed in seven modes, so recite whatever is easy from it."

Muslim 1899

Sahih

حدثنا يحيى بن يحيى قال قرأت على مالك عن ابن شهاب عن عروة بن الزبير عن عبد الرحمن بن عبد القاري قال سمعت عمر بن الخطاب يقولا سمعت

هشام بن حكيم بن حزام

يقرأ سورة الفرقان على غير ما أقرؤها وكان رسول الله ﷺ أقرأنيها فكدت أن أعجل عليه ثم أمهلته حتى انصرف ثم لببته بردائه فجئت به رسول الله ﷺ فقلت يا رسول الله إني سمعت هذا يقرأ سورة الفرقان على غير ما أقرأتنيها فقال رسول الله ﷺ أرسله اقرأ فقرأ القراءة التي سمعته يقرأ فقال رسول الله ﷺ هكذا أنزلت ثم قال لي اقرأ فقرأت فقال هكذا أنزلت إن هذا القرآن أنزل على سبعة أحرف فاقرءوا ما تيسر منه

مسلم 1899صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Muslim
Book
Virtues of the Quran and what relates to it
Chapter
Clarification that the Quran was revealed in seven modes and clarification of its meaning
Numbering
Darussalam 1899
Muslim 1899