Philip the Arab and Christianity that appear—save for one reference to Ishmael—figure in the political history of the first three centuries of the Christian era. To Eusebius, the Saracens of the 4th century are direct-line descendants of the biblical Ishmaelites, descendants of the handmaid, Hagar, and the patriarch, Abraham. They are thus outcasts, beyond God's Covenant with the favored son of Abraham, Isaac. The twin images of the Ishmaelite and the Saracen—outcasts and "latrones", raiders of the frontiers—reinforce each other and give Eusebius' portrait of the Arab nation an unhappy color. He may have been reluctant to associate the first Christian emperor with a people
Abraham but which God now promises to Abraham and his progeny. Various candidates are put forward who might inherit the land after Abraham; and, while promises are made to Ishmael about founding a great nation, Isaac, Abraham's son by his half-sister Sarah, inherits God's promises to Abraham. Abraham purchases a tomb (the Cave of the Patriarchs) at Hebron to be Sarah's grave, thus establishing his right to the land; and, in the second generation, his heir Isaac is married to a woman from his own kin, thus ruling the Canaanites out of any inheritance. Abraham later marries Keturah and has six