Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates: I have offered prayer behind the Prophet (peace and blessings of Allah be upon him), Sayyiduna Abu Bakr (may Allah be pleased with him), Sayyiduna Umar (may Allah be pleased with him), and Sayyiduna Uthman Ghani (may Allah be pleased with him), and I did not hear any one of them reciting «بِسمِ اللهِ الرَّحْمَنِ الرَّحِيمِ» aloud.