While I was praying, the Prophet (ﷺ) passed by and called me, but I did not go to him till I had finished my prayer. When I went to him, he said, "What prevented you from coming?" I said, "I was praying." He said, "Didn't Allah say" "O you who believes Give your response to Allah (by obeying Him) and to His Apostle." (8.24) Then he added, "Shall I tell you the most superior Sura in the Quran before I go out of the mosque?" When the Prophet (ﷺ) intended to go out (of the Mosque), I reminded him and he said, "That is: "Al hamdu-li l-lahi Rabbil-`alamin (Surat-al-fatiha)' which is the seven oft repeated verses (Al-Mathani) and the Grand Quran which has been given to me."
Sahih al-Bukhari Book 65, Hadith 225
← Previous Hadith (While we were going for the Battle of Tabuk and when we reached the places of the dwellers of Al- Hijr), Allah's Messenger (ﷺ) said about the dwellers of Al-Hijr (to us). "Do not enter (the dwelling places) of these people unless you enter weeping, but if you weep not, then do not enter upon them, lest you be afflicted with what they were afflicted with."

Sahih al-Bukhari Book 65, Hadith 224 Next Hadith → Allah's Messenger (ﷺ) said, "The Um (substance) of the Quran is the seven oft-repeated verses (Al- Mathaini) and is the Great Quran (i.e. Surat-al-Fatiha).

Sahih al-Bukhari Book 65, Hadith 226