UmmSharik Al-Ansari said:
"The Messenger of Allah (ﷺ) commanded usto recite the Opening of the Book (Al-Fatihah) in the funeralprayer." (FR)
English reference (FR): Vol. 1, Book 6, Hadith 1496 (FR)
Arabic reference (FR): Book 6, Hadith 1563 (FR)