Round the Law (Torah) had gathered a vast number of explanatory directions, and a certain number of traditional additions known as “Haggadah.” The first of these, the directions or explanations, were known by the term “Halachah.”[153] It had become necessary, seeing that the Law of Moses was accepted as the divine code for the guidance of the Chosen People, to explain and enlarge it further, so as to apply its brief enactments to all the conditions of everyday life. Some few of these Halachah were traditionally derived from Moses himself. Others had probably been composed very early in the schools of the prophets; yet more were the work of the Scribes,[154] a numerous class of teachers which had arisen after the return from exile in the days of Ezra. These Halachah (we use the well-known expression in preference to the more accurate plural form Halachoth; the same course has been followed in that of the expression “Haggadah”) had been largely augmented in the half-century preceding the catastrophe of _A.D._ 70. The group of eminent Rabbis who arose after the fall of the City and Temple, and who set themselves the task of reconstituting Israel on a new and purely religious basis, took these Halachah, studied them, meditated on them,--no doubt recast many of them to suit the new position of the people, now that the Temple and its complicated ritual of sacrifice and public prayer had disappeared, and framed them into an elaborate system of regulations, thus pointing out how the Law might be rigidly observed in all the relations of ordinary life. This great and elaborate work is termed the Mishnah[155]--or “Repetition,”--the term originally derived from the method in which it was elaborated. It was not written down in the first instance, but was _repeated_ again and again by the more famous teachers and heads of schools to their pupils. The term “Mishnah” came in time to signify “the second Law,” but that was not the original meaning; it belonged to a period when the whole instruction was _oral_. The period of the elaboration of these Halachah (rules) and Haggadah (tradition) lasted somewhere about a hundred years or a little more. The great teachers who busied themselves in this work are ordinarily termed the Mishnic Rabbis--the Talmud term for them being Tannaim. In the last years of the second century the Mishnah or first part of the Talmud was virtually closed, and the great Rabbinic schools then busied themselves in further commenting upon and explaining the Halachah (rules) and Haggadah (traditions) of the Mishnah; these further comments and explanations are known as the Gemara.