Now what kind of question is that for a spiritual blog-site? Actually it should be a matter of serious concern when one realizes that there is a people among us who love to rewrite history. Every cult has gained power by confessing faith in the Scriptures and then adding to and/or subtracting from them. In some cases, entirely new translations of the Bible have come about by such shenanigans. The Jehovah's Witnesses [so called] are in this camp. The Mormons and many others have their "companion pieces" that supplement Biblical truth with deceptive lies.
Then there is Islam. Their Koran is a statement of faith in the Hebrew-Christian Scriptures coupled with gross denials of all the major truths therein. The characters look familiar, but we hear them saying different things, doing different activities, than in the Bible.
Take the Isaac/Ishmael thing for example. We know from history that goes back over 4000 years that Isaac was the son promised of God, even though Ishmael was Abraham's firstborn. The Koran, with its loose ways in regards to truth, has it that Ishmael is the son of promise, Isaac merely a distraction.
Not only was Isaac the promised son, to Isaac was to be given the Promised Land, through Jacob and his twelve sons, which become twelve "tribes", which together became the nation Israel.
Ishmael was to have material blessing also, a "great nation" he was to become. He also had 12 sons who fathered 12 tribes.
And these are the names of the sons of Ishmael, by their names, according to their generations: The firstborn of Ishmael, Nebajoth, and Kedar, and Adbeel, and Mibsam, and Mishma, and Dumah, and Massa, Hadad and Tema, Jetur, Naphish and Kedmah. These are the sons of Ishmael... twelve princes according to their nations." Genesis 25:12-16.
But the land from the Great Sea to the Jordan was not a part of Ishmael's inheritance. History bears out what God promised to both sons. And many of the Arabians, as well as other Middle Eastern peoples, come to us from Ishmael.
David Gibson and his son have from 1932 been researching the whereabouts of the descendants of Ishmael. It is a fascinating study and I recommend my readers to go to their "Nabatea" site for further information.
They found, for example, that Roman historian Josephus, usually quite a reliable source, identified the Nabateans of his day with the first son of Ishmael, Nebajoth. Roman and Greek historians referred to these Nabateans as "Arabs" in some of their writings. They covered much of Arabia in that era.
Though we know more about the first son than any of the other sons, it is clear that more than one Ishmaelite tribe went into that part of the world. Kedar is associated with Arabia by Ezekiel. Archaeological finds place Massa in the Arabian peninsula. There is a Hadad tribe there even now, which has largely become Christian. Babylonian-Assyrian records place Tema in Arabia.
So on it goes. Other Ishmaelite tribes went towards Egypt, stayed in the Sinai peninsula next door, etc. But none of them went to old Canaan.
When Isaac (Genesis 26) was about to go to Egypt, God stopped him and told him the land where he was standing was where he belonged. They call that spot Gaza today. That's Jewish territory, as is everything north and east of it. The son of promise was promised Canaan. 400 plus years later, Canaan is what he received, while the Arabian countryside was being peopled by the sons of Ishmael, the first true Arabs.