The Messenger of Allah ﷺ said, "Jibreel recited the Quran to me in one mode, but I kept asking him for more, and he kept granting me more, until it reached seven modes."
أن رسول الله ﷺ قال: أقرأني جبريل على حرف، فراجعته فلم أزل أستزيده ويزيدني حتى انتهى إلى سبعة أحرف.
Bukhari narrated it in "Beginning of Creation" (3219) and in "Virtues of the Quran" (4991), and Muslim narrated it in "Prayer of the Traveler" (819), both from the hadith of Ibn Shihab Zuhri, who said, Ubaydullah bin Abdullah bin Utba told me that Ibn Abbas told him, and he related the hadith, both wordings being the same.Muslim said, Ibn Shihab said, "It has reached me that these seven forms only apply to matters that remain constant, in which there is no difference regarding what is permitted or forbidden."