Sahih Bukhari

Narrated Abu Sa`id Al-Mu'alla:While I was praying, the Prophet (ﷺ) called me but I did not respond to his call. Later I said, ""O Allah's Apostle! I was praying."" He said, ""Didn't Allah say: 'O you who believe! Give your response to Allah (by obeying Him) and to His Apostle when he calls you'?"" (8.24) He then said, ""Shall I not teach you the most superior Surah in the Qur'an?"" He said, '(It is), 'Praise be to Allah, the Lord of the worlds. ' (i.e., Surat Al-Fatiha) which consists of seven repeatedly recited Verses and the Magnificent Qur'an which was given to me