The relationship between Islam and the Church of the East varied according to the political situation. Muhammad is said to have had an East Syriac teacher named Sergius Bahira. While this may be merely legend, the Prophet of Islam was nonetheless influenced by the Christian missionaries with whom he became acquainted in Yemen and along the trade route to Iraq. Thus his view of resurrection, for example, may have been colored by the East Syrians he had known in his youth. The earliest suras of the Qur’an suggest apocalyptic influences. In the tenth century the Arab author Abu l-Farag al-Isbahani († 967) reported that Muhammad had heard the eschatological preaching of the East Syriac bishop (?) Quss b. Saida while in Ukaz, and this shaped his thinking. In any case, Muhammad had a positive impression of the Church of the East.