http://www.jihadwatch.org/2011/07/ibn-warraq-the-judeo-christian-origins-of-islam-part-9.html
Part 1 here; part 2 here; part 3 here; part 4 here; part 5 here, part 6 here, part 7 here, part 8 here.

CC go on to argue that the town we now know as Mecca in central Arabia (Hijaz) could not have been the theater of the momentous events so beloved of Muslim tradition. Apart from the lack of any early non- Muslim references to Mecca, we do have the startling fact that the direction in which the early Muslims prayed (the qibla) was northwest Arabia. The evidence comes from the alignment of certain early mosques, and the literary evidence of Christian sources. In other words, Mecca, as the Muslim sanctuary, was only chosen much later, by the Muslims, in order to relocate their early history within Arabia, to complete their break with Judaism, and finally establish their separate religious identity.

There are many obscure passages in the Koran that can only be elucidated by reference to the Pentateuch or Psalms. Without going into the recondite philology of his arguments [for the details, see Michael Schub, The Secret Identity of Dhu l’Kifl, in ed Ibn Warraq, What the Koran Really Says, pp. 394-395], we can mention Michael Schub’s identification of the term “Dhu l’Kif”, which has puzzled commentators for centuries, with Melchizedeq mentioned in Genesis 14:16, Hebrews [NT] Chapters V and VII, Psalms CX. Melchizedeq is the one of who gets his share, who receives one-tenth of Abraham’s spoils, and who is to be ranked above the Levites, whose primary function under the Law was to collect the tithes, and that is precisely the sense of the Arabic Dhu l’Kifl.

Even more startling is the following example:

Surah III. 95-96; “Certainly the first house appointed for men is the one at Bakkah, blessed and a guidance for the nations. In it are clear signs: (it is) the Place of Abraham; and whoever enters it is safe; and pilgrimage to the House is a duty which men owe to Allah — whoever can find a way to it. And whoever disbelieves, surely Allah is above the need of the worlds.”

Many translations simply add in brackets after Bakkah (Mecca), without a word of explanation. Modern Western commentators may add a footnote saying Bakkah was an alternative spelling of Mecca, as does the Encyclopaedia of Islam, Second Edition. The classical Arabic commentary known as Tafsir al-Jalalayn completed approximately in 1467 C.E says, “The use of Bakkah rather than Mecca reflects a Meccan dialect; it is called that because it bears down (bakka) on the neck of tyrants. The angels built it before the creation of Adam whereas al-Aqsa in Jerusalem was built after that.” Here is one Muslim translator’s comments, “Bakkah is the same as Makkah [Mecca] [referrring the reader to Al-Isfahani’s Dictionary of the Qur’an] from tabakk meaning the crowding together of men [ Commentary of Fakhr al-Din Razi]. Others say it is from a root meaning the breaking of the neck, and the name is given to it because whenever a tyrant forced his way to it, his neck was broken [Razi]. Some think that Bakkah is the name of the mosque or the House itself that is in Makkah [Mecca]. The Jews and Christians are told that the Temple at Jerusalem was erected long after Abraham, while the Holy House at Makkah [Mecca] was there even before Abraham, and was in fact, the first House on earth for the worship of the Divine Being.” In other words, the Muslim commentators really do not have a clue as to its meaning.