Book of Jubilees: The Book of Jubilees: The Dwelling-plac...
12. And Ishmael and his sons, and the sons of Keturah and their sons, went together and dwelt from Paran to the entering in of Babylon in all the land which is towards the East facing the desert. 13. And these mingled with each other, and their name was called Arabs, and Ishmaelites.