The human family came from the 3 sons of Noah; Shem, Ham and Japheth. Noah's three sons Shem, Ham and Japheth, from which were derived Semites, Hamites and Japhetites, certain of Noah's grandsons including Elam, Ashur, Aram, Cush, and Canaan, from which the Elamites, Assyrians, Arameans, Cushites and Canaanites, as well as further descendants including Eber (from which "Hebrews"), the hunter-king Nimrod, the Philistines and the sons of Canaan including Heth, Jebus and Amorus, from which Hittites, Jebusites and Amorites. The Flood story tells how Noah and his three sons Shem, Ham, and Japheth, together with their wives, were saved from the Deluge to repopulate the Earth. Shem's name means "name" or "fame". Through his descendant, Eber, Shem became the ancestor of Abraham and thus the Israelites Ham is Noah’s youngest son Template:Genesis 9:18-25 the forefather of Cush, Egypt, and Put, and of Canaan, whose lands include portions of Africa, Arabia, Syria-Palestine and Mesopotamia. Japheth is the oldest son. His name is associated with the mythological Greek Titan Iapetos, and his sons include Javan, the Greek-speaking cities of Ionia. https://en.wikipedia.org/wiki/Generations_of_Noah Which 'line' do Arabs come forth from? And regardless, why would cousin fight against cousin?
