Yahya related to me from Malik from Humayd at-Tawil that Anas ibnMalik said, "I stood behind Abu Bakr and Umar and Uthman and none ofthem used to recite 'In the name of Allah, the Merciful, theCompassionate' when they began the prayer." (IT)
App reference (IT): Book 3, Hadith 31 (IT)
USC-MSA web (English) reference: Book 3, Hadith 31 (IT)
Arabic reference (IT): Book 3, Hadith 178 (IT)