In beginning of ninth and tenth century, Qaraites were concentrated in Iraq and Persia, but, in the middle of the tenth century, they began moving westward to Jerusalem, North Africa, and Spain. During this time period, Qaraites lived throughout the Jewish-inhabited world. In every important city besides those in France and Germany, a Qaraite community could be found alongside each Rabbanite community. Many of the Qaraites were great philosophers, writers, and wealthy merchants; some were invested with high political power. In Cairo, Qaraites were so powerful and influential that many Rabbanites left the fold for Qaraism, until Rambam came to Cairo in 1166 and stopped this drift by improving the political power of the Rabbanites. It is thus understandable why Rambam would seek to modify Jewish practices to widen the separation between Rabbanites and Qaraites.
R. Chananel (990 – 1053) and R. Yitchak Alfasi (1013 – 1103), the first rishonim to make the six-hour wait an absolute requirement, lived in Fez, Kairouan, and Spain, side-by-side with Qaraite communities. As the Qaraites allowed themselves to eat milk and meat together over the course of the tenth century, they became nicknamed ‘the eaters of milk and meat’. They surely influenced some from the Rabbanite community. In order to protect the Halacha, highlight their symbolic differences, and erect a social barrier between the two camps, these leaders extended the original kinuach ve’hadacha obligation to a six hour wait.
Some historians believe that the Qaraites of the early Middle Ages counted for close to half of the total Jewish population. Furthermore, recent analysis of Cairo Geniza documents shows that Qaraite and Rabbanite communities of North Africa and Eretz Yisrael of the tenth through thirteenth centuries collaborated in legal affairs, political endeavors, and commerce. There were even frequent mutually respectful Qaraite-Rabbanite marriages. The two communities were dependent on each other in many ways. An excellent description of this historical setting is found in Heresy and the Politics of Community by Marina Rustow (2008). The need to defend the rabbinic Halacha is understood better against such an historical backdrop. As the divide between the communities was sometimes blurred, reinforcement was necessary. It is understandable why we find a Rabbanite response to Qaraite leniencies from North African Rabbanite authorities and not from the heirs of the Gaonate in Iraq. This is because the center of Qaraite activity had already migrated from Iraq to the Mediterranean Basin over the course of the tenth century.
During the tenth and eleventh centuries, Rabbanites from all over the Mediterranean would make yearly pilgrimages to Jerusalem for Sukkos. On Hosha’na Rabba, the custom was for all to gather on Har ha’Zaisim and, amongst other things, declare blessings and bans. In 1029 and 1038, the Rabbanites proclaimed a ban against the Qaraites. It is the wording of these charamim which is very revealing. The ban was worded “against the eaters of meat and milk”.
Rustow explains the deeper context and meaning behind the ban:
…the Rabbanites and the Qaraites in the Fatamid realm conducted regular professional and personal relations. The ban’s aim was not to correct Qaraite religious behavior, but to achieve symbolic or ritual separation between the two groups. …. the principle violation with which the Qaraites stood charged- challenging the rabbinic claim to exclusive authority in interpreting biblical law …. The ban was couched, by a synecdoche that stood for an entire theological aberration, in terms of a specific infringement: eating meat with milk.
The milk and meat mixing of the Qaraites symbolized the divide between the Qaraite and Rabbanite camps. It is clear why the leading rabbinic sages of this era would fortify and tighten this particular area of law.
Tzvi H. Adams, “Waiting Six Hours for Dairy – A Rabbanite Response to Qaraism”, Seforim Blog (11 August 2015) [http://seforim.blogspot.com/2015/08/waiting-six-hours-for-dairy-rabbanite.html]