Narrated Abu Hurairah:
that the Messenger of Allah (ﷺ) said: "Al-Hamdulillah is Umm Al-Qur'an and Umm Al-Kitab and the seven oft-repeated." (ES)
English reference (ES): Vol. 5, Book 44, Hadith 3124 (ES)
Arabic reference (ES): Book 47, Hadith 3415 (ES)