I have also provided some links, but I have not bothered to thoroughly check up on the veracity of most of what is found in these, so caveat surfor.
first excerpt:[p. 90]"Early Muslim compendia of hadith include a number of traditions according to which the Prophet decided to expel all non-Muslims from the Arabian peninsula. In some compendia we find traditions about the expulsion of the polytheists, and separate utterances about the expulsion of the Jews and the Christians. The traditions are repeated in chapters dealing with various issues of religious law and appear in variant versions. Most of them deal with the expulsion of the Jews and the Christians from the areas of Medina, Khabyar and Najran. The expulsion from Medina is said to have been carried out by the Prophet; he intended to expel the Jews of Khabyar as well, but allowed them to remain there on the condition that they continue to work the land and yield half of the agricultural produce to the Muslims. Eventually, Umar b. al-Khattab carried out the Prophet's wish and expelled the Jews of Khaybar to Jericho and Tayma. Once this development took place, the clauses in 'ahd al-umma ('Constitution of Medina') bestowing legitimacy on the existence of the Jewish faith in Medina became problematic and had to undergo substantial reinterpretation far removed from their primary meaning."
second excerpt:[pp. 91-93]"According to a tradition reported by Malik b. Anas, the last thing the Prophet said before his death was: 'May God fight the Jews and the Christians! They transformed the tombs of their prophets into mosques. Two religions will not remain in the land of the Arabs.' The last sentence was also mentioned by 'Umar when he decided to expel the Jews from Khaybar.
The tradition about the expulsion of the Jews from Medina, reported by Bukhari, seems to imply that the reason for the Prophet's decision was his desire to take over their landed property. The traditions concerning the aftermath of the Banu Qurayza massacre also contain descriptions of distribution of land to the muhajirun. In most traditions of legal import, however, the reason given for the expulsion is the intention to bring about religious uniformity in the Arabian peninsula: the Prophet is reported to have said that no two religions would coexist there (la yajtami'u dinani fi jazirat al-'arab). The reference to the Jews in this context is of particular significance, most Jews are monotheists, and if they are ordered to leave, the expulsion of other infidels follows as a matter of course.
"According to another tradition, the decision to expel the Jews and the Christians was the last decision taken by the Prophet before his death; the implication of this seems to be that this decision remains valid forever, becaues nobody has the authority to revoke the Prophet's injunctions after his death . . . .
"The traditions concerning the expulsion of non-Muslims do not all use the same terms to define the area which they must abandon. Sometimes only Medina is mentioned; but in most cases the terms used are ard al-'Arab, ard al-Hijaz, jazirat al-'Arab, mulk al-'Arab, Khaybar and Wadi al-Qura. Geographically speaking, these terms are not quite clear; some traditionists deem it therefore necessary to specify the boundaries of the area affected by the explusion order. There are also separate traditions about the expulsion of Christians from Najran. Regarding the Zoroastrians of 'Uman, there is a tradition according to which the conquering Muslims gave them the choice to embracing Islam or going into exile. The Zoroastrians chose to leave and abandoned their possessions, which were transformed into state lands (sawafi). On the other hand, the Yemen was not included in the areas that had to be evacuated by the non-Muslims.
"The need for religious uniformity is discussed not only in relation to the Arabian peninsula. The basis for these discussions are prophetic traditions in which the need for religious uniformity is formulated in general terms and is not geographically restricted. In his Sharh al-siyar al-kabir, the Hanafi scholar al-Sarakhsi (d. 1090) discusses the question whether it is permissible for the People of the Book to live in Muslim cities. He replies in the affirmative, because shared residence will, in his opinion, enable the People of the Book to see the beauty of Islam. He mentions, however, the view of al-Halwa'i, who maintains that this rule applies only if non-Muslims are few and their residence will not adversely affect Muslim rituals; if they are numerous, and their residence may have such an adverse effect, they are prevented from living in teh city and are required to live in an area which is not populated by Muslims. Seth Ward has drawn attention to the view of al-Tabari, according to whom 'the legal standing of all Islamic lands is the same as that of the Arabian peninsula.'"
third excerpt:[pp. 97-99]"Qur'an 8:39 enjoins the Muslims to 'fight ... till there is no fitna and the religion is God's entirely.' The crucial word fitna is difficult and the commentators most usually explain it as 'infidelity' or 'polytheism' (kufir, shirk). It seems, however, that in this verse fitna conveys primarily the idea of the unbelievers trying to induce the Muslims to abandon their religion. This fits the primary meaning of fatana and its usage in some early documents attributed to the Prophet. It is also compatible with the historical context of early Islam, when the few Muslims were under constant pressure of their powerful adversaries to revert to their former faith. If our understanding is correct, the verse enjoins the Muslims to fight the infidels and weaken them to such an extent that they would no longer be capable of promoting apostasy among the Muslims.
"The Qur'anic commentators go far beyond this meaning of the concept. Theough it is not easy to find an etymological justification for this, the prevalent understanding of fitna in exegesis is polytheism (shirk) or infidelity (kufr). Al-Tabari quotes and exegetical tradition according to which the verse command the Muslims to create a situation in which 'no infidelity will coexist with our religion' (la yakuna ma'a dinikum kuf). He also stresses that even if the polytheists stop fighting, the Muslims must fight them until they embrace Islam . . . .
"The desire to achieve religious uniformity is expressed also in the hadith. Perhaps the most explicit tradition in which Islam enunciated this purpose reads:I was commanded to fight the people until they say: There is no god except Allah.' Once they have said this, they have rendered their lives and possessions inviolable by me, except on the ground of the (unfulfilled) duties incumbent on them; it will be up to Allah to call them to account."This tradtion has been preserved in several versions which are essential for our understanding of its significance. The shortest and probably earliest version, which is quoted above, includes the minimal requirement for conversion: the affirmation of God's oneness. [M. J.] Kister has shown that soon afterward the second shahada, attesting to the prophethood of Muhammad, and the obligation to pray and pay the zakat was added. The expanded version reads:I was commanded to fight the people until they say: 'There is no god except Allah, and Muhammad is the messenger of Allah; and until they perform the prayer and pay the poor tax.' If they do this, they have thereby rendered their lives adn possessions inviolable to me . . . ."This version reflects the policy ascribed to Abu Bakr at the time of the ridda wars: he demanded that the rebellious tribes conform not only in the purely religious sense, but also pay their share in financing the nascent Muslim state."
