It wasnarrated that from 'Amr bin Shu'aib, from his father, from hisgrandfather, that the Messenger of Allah (ﷺ) said:
"Every prayerinwhich Fatihatil-Kitab (the Opening of the Book) is not recited, itisdeficient, it is deficient." (RU)
English reference (RU): Vol. 1, Book 5, Hadith 841 (RU)
Arabic reference (RU): Book 5, Hadith 890 (RU)