There are problems with this theory, however. Problems that leads one to wonder if Islam has hi-jacked the very lineage of Abraham. First of all, Hagar was an Egyptian woman, NOT an Arab. Arabs were mentioned by the Jews of that time and so were Egyptians and so there was not reason to assume that Hagar would have been referred to as an Egyptian had she actually been an Arab.
Secondly, Ishmael did NOT settle in Mecca as Muhammadans claimed so much later, but the Bible clearly states that he settled near Egypt and married an Eyptian woman Gen 21:21 and Gen 25: 12-18.
The Bible further states that all Ishamael's sons settle near Egypt as you will see in the cited verses from Genesis.
Now, Muhammad claimed that the Bible had been corrupted and that is why 'allah' sent him to straighten things out as he had sent Jesus before him. But Jesus never claimed that the Judaic writings were corrupted or wrong in any way, only that there was a deeper relationship possible with God. Muhammad liked to place himself as the culmination of the Abrahamic prophets and his message as the zenith of Abrahamic religion.
The contradictions of this assumption are much more than most logical people can ignore, however, such as the draconian system of justice and dark ages practices like genital mutilation and the forced marriages of adult men to child brides. Could these contradictions be accounted for by the fact that Islam is probably not even a legitimate member of the Abrahamic religions in the first place?
The only "proof" we have that Muhammad was a decendent of Ishmael is the Muslims word for it. But the evidence that Ishmael did NOT settle anywhere NEAR Arabia has been written and known since the earliest Biblical texts!
Add to that the fact that this argument of Muhammad's links to Abrahamic lineage is a relatively NEW phenomenon, and one begins to wonder if the whole claim of ties to Hagar the Egyptian slave of Abraham and Sarah aren't all just another Islamic hi-jacking.
An excerpt from a study on this topic states the following:
http://www.answering-islam.org/Shamoun/ishmael.htmThis leads us to our final problem. The veracity of these records is based primarily on the assumption that Ishmael settled in Mecca and married a Jurhumite woman. Since Ishmael did not settle in Mecca, but in Paran, and married an Egyptian this means that neither Kedar nor Nebaioth could have been the ancestor of the Meccan Arabs.
There are certain Islamic scholars who readily admit this fact. The late Egyptian Professor, Dr. Taha Husayn, considered one of the foremost authorities on Arabic literature, while commenting on the story of Abraham and Ishmael building the Kabah, states:
"The case for this episode is very obvious because it is of recent date and came into vogue just before the rise of Islam. Islam exploited it for religious reasons." (As quoted in Mizan al-Islam by Anwar al-Jundi, p. 170 as found in Behind the Veil, p. 184, source; bold emphasis ours)
In his rebuttal to Dr. Robert A. Morey's book Islamic Invasion, W. Aliyyuddin Shareef, is honest enough to admit:
"In pre-Islamic times Ishmael was never mentioned as the Father of the Arabs." (Shareef, In response to Robert Morey's Islamic Invasion, pp. 3-4; bold emphasis ours)
Writer Camilla Adang, in a footnote from her book Muslim Writers on Judaism and the Hebrew Bible from Ibn Rabban to Ibn Hazm, mentions:
... Ishmael is considered the progenitor of the Arabs. Dagon (1981) has shown that this idea is an Islamic construction AND THAT NO CONNECTION BETWEEN ISHMAEL AND THE ARABS HAD EVER BEEN MADE IN THE PRE-ISLAMIC PERIOD. Already in the first Islamic century, however, Ishmael came to symbolize the Islamic Umma, and biblical passages about Ishmael were taken to refer to Muhammad, the Arabs, or the Muslim community. (Adang, p. 147, fn. 37: E.J. Brill Academic Publishers; August 1997 ISBN: 9004100342; bold and capital emphasis ours)
Former Muslim turned to atheist Ibn Warraq writes:
We are told that [Abraham] was born in Chaldea, and that he was the son of a poor potter who earned his living by making little clay idols. It is scarcely credible that the son of this potter went to Mecca, 300 leagues away in the tropics, by way of impassable deserts. If he was a conqueror he no doubt aimed at the fine country of Assyria; and if he was only a poor man, as he is depicted, he founded no kingdoms in foreign parts. — Voltaire
For the historian, the Arabs are no more the descendents of Ishmael, son of Abraham, than the French are of Francus, son of Hector. — Maxime Rodinson
It is virtually certain that Abraham never reached Mecca. — Montgomery Watt
The essential point ... is that, where objective fact has been established by sound historical methods, it must be accepted. — Montgomery Watt
According to Muslim tradition, Abraham and Ishmael built the Kaaba, the cube-like structure in the Sacred Mosque in Mecca. But outside these traditions there is absolutely no evidence for this claim - whether epigraphic, archaelogical, or documentary. Indeed Snouck Hurgronje has shown that Muhammad invented the story to give his religion an Arabian origin and setting; with this brilliant improvisation Muhammad established the independence of his religion, at the same time incorporating into Islam the Kaaba with all its historical and religious associations for the Arabs. (Ibn Warraq, Why I Am Not A Muslim [Prometheus Books, Amherst NY 1995], p. 131; bold emphasis ours)
Finally, Islamicist Alfred Guillaume notes:
"... there is no historical evidence for the assertion that Abraham or Ishmael was ever in Mecca, and if there had been such a tradition it would have to be explained how all memory of the Old Semitic name Ishmael (which was not in its true Arabian form in Arabian inscriptions and written correctly with an initial consonant Y) came to be lost. The form in the Quran is taken either from Greek or Syriac sources." (Alfred Guillaume, Islam [Penguin Books Inc., Baltimore, 1956], pp. 61-62)
In case Muslims want to claim that the biblical text has been tampered with, it should be pointed out that the Jews would have no reason to distort the location of Paran since there was neither Christians nor Muslims around when these texts were written. Therefore, claiming textual distortion will not solve the problem for the Muslims.
Perhaps there are only two truly Abrhamic religions and Islam is, once again, sneaking it's way on someone else's airplane in hopes of smashing into the twin towers of a very old and beloved establishment?