Arabic Christian anti-Islamic literature was apocalyptic, polemic, and lurid in its invented tales

Evidence

Among Arabic-speaking Christians a whole literature on this theme developed; it was apocalyptic, because it was concerned with prophecies of the end of the reign of the Arabs; it was also polemic and retrospective, describing how Bahira was forced to reveal the Christian mysteries to Muhammad, how the people were deceived by a cow that was supposed to have come from Heaven, bearing the Qur’an on her horns; it was a literature that attacked the person, history and character of the Prophet. — Norman Daniel, Islam and the West, 56