Introduction to Mishna Torah
Thus, Ravina, Rav Ashi, and their colleagues represent the final era of the great Sages of Israel who transmitted the Oral Law. They passed decrees, ordained practices, and put into effect customs. These decrees, ordinances, and customs spread out among the entire Jewish people in all the places where they lived.
After the court of Rav Ashi composed the Talmud and completed it in the time of his son, the Jewish people became further dispersed throughout all the lands, reaching the distant extremes and the far removed islands. Strife sprung up throughout the world, and the paths of travel became endangered by troops. Torah study decreased and the Jews ceased entering their yeshivot in the thousands and myriads, as was customary previously. Instead, individuals, the remnants whom God called, would gather in each city and country, occupy themselves in Torah study, and [devote themselves] to understanding the texts of the Sages and learning the path of judgment from them.
Every court that was established after the conclusion of the Talmud, regardless of the country in which it was established, issued decrees, enacted ordinances, and established customs for the people of that country - or those of several countries. These practices, however, were not accepted throughout the Jewish people, because of the distance between [their different] settlements and the disruption of communication [between them]. Since each of these courts were considered to be individuals - and the High Court of 71 judges had been defunct for many years before the composition of the Talmud -people in one country could not be compelled to follow the practices of another country, nor is one court required to sanction decrees which another court had declared in its locale. Similarly, if one of the Geonim interpreted the path of judgment in a certain way, while the court which arose afterward interpreted the proper approach to the matter in a different way, the [opinion of the] first [need] not be adhered to [absolutely]. Rather, whichever [position] appears to be correct - whether the first or the last - is accepted.
These [principles apply regarding] the judgments, decrees, ordinances, and customs which were established after the conclusion of the Talmud. However, all the matters mentioned by the Babylonian Talmud are incumbent on the entire Jewish people to follow. We must compel each and every city and each country to accept all the customs that were put into practice by the Sages of the Talmud, to pass decrees parallelling their decrees, and to observe their ordinances, since all the matters in the Babylonian Talmud were accepted by the entire Jewish people.
