Abu Saeed bin Mualla reported,

The Prophet ﷺ passed by me while I was praying. He called me, but I did not come to him until I had finished my prayer. Then I came to him, and he asked, "What kept you from coming to me?"I replied, "I was praying."He said, "Did Allah not say, 'Believers, respond to Allah and the Messenger when he calls you to that which gives you life' [Anfal 8:24]?"Then he said, "Shall I teach you the greatest surah in the Quran before I leave the mosque?"The Prophet ﷺ then went to leave the mosque, and I reminded him. He said, "It is 'Praise be to Allah, Lord of the worlds' [Fatihah 1:2]. It is the seven oft-repeated verses and the Magnificent Quran that has been given to me."

Bukhari 4703

Sahih

حدثني محمد بن بشار حدثنا غندر حدثنا شعبة عن خبيب بن عبد الرحمن عن حفص بن عاصم

عن أبي سعيد بن المعلى قال

مر بي النبي ﷺ وأنا أصلي فدعاني فلم آته حتى صليت ثم أتيت فقال ما منعك أن تأتيني فقلت كنت أصلي فقال ألم يقل الله {يا أيها الذين آمنوا استجيبوا لله وللرسول إذا دعاكم لما يحييكم} ثم قال ألا أعلمك أعظم سورة في القرآن قبل أن أخرج من المسجد فذهب النبي ﷺ ليخرج من المسجد فذكرته فقال الحمد لله رب العالمين هي السبع المثاني والقرآن العظيم الذي أوتيته

البخاري 4703صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Tafsir
Chapter
His saying, "And We have certainly given you seven of the often repeated verses and the great Quran"
Numbering
Darussalam 4703
Bukhari 4703