Source: CHAPTER 15. HOW THE NATION OF THE TROGLODYTES WERE DERIVED FROM ABRAHAM BY KETURAH. (Christian Classics Ethereal Library) 2021 A.D.
From the source, “ABRAHAM after this married Keturah, by whom six sons were born to him, men of courage, and of sagacious minds: Zambran, and Jazar, and Madan, and Madian, and Josabak, and Sous. Now the sons of Sous were Sabathan and Dadan. The sons of Dadan were Latusim, and Assur, and Luom. The sons of Madiau were Ephas, and Ophren, and Anoch, and Ebidas, and Eldas. Now, for all these sons and grandsons, Abraham contrived to settle them in colonies; and they took possession of Troglodytis, and the country of Arabia the Happy, as far as it reaches to the Red Sea. It is related of this Ophren, that he made war against Libya, and took it, and that his grandchildren, when they inhabited it, called it (from his name) Africa. And indeed Alexander Polyhistor gives his attestation to what I here say; who speaks thus: “Cleodemus the prophet, who was also called Malchus, who wrote a History of the Jews, in agreement with the History of Moses, their legislator, relates, that there were many sons born to Abraham by Keturah: nay, he names three of them, Apher, and Surim, and Japhran. That from Surim was the land of Assyria denominated; and that from the other two (Apher and Japbran) the country of Africa took its name,”