It wasnarrated that Abu Sa'eed said:
"The Messenger of Allah (ﷺ)said: 'There is no prayer for the one who does not recite in everyRak'ah: Al-Hamd (Al-Fatihah) and a Surah whether in an obligatoryprayer or another.'" (IT)
English reference (IT): Vol. 1, Book 5, Hadith 839 (IT)
Arabic reference (IT): Book 5, Hadith 888 (IT)