The author of Matthew wrote for a community of Greek-speaking Jewish Christians located probably in Syria (Antioch, the largest city in Roman Syria and the third-largest in the empire, is often mentioned).[29] Unlike Mark, Matthew never bothers to explain Jewish customs, since his intended audience was a Jewish one; unlike Luke, who traces Jesus' ancestry back to Adam, father of the human race, he traces it only to Abraham, father of the Jews; of his three presumed sources only "M", the material from his own community, refers to a "church" (ecclesia), an organised group with rules for keeping order; and the content of "M" suggests that this community was strict in keeping the Jewish law, holding that they must exceed the scribes and the Pharisees in "righteousness" (adherence to Jewish law).[30] Writing from within a Jewish-Christian community growing increasingly distant from other Jews and becoming increasingly Gentile in its membership and outlook, Matthew put down in his gospel his vision "of an assembly or church in which both Jew and Gentile would flourish together".[31]