Musar for Sanhedrin 54:5
ממאי דילמא בפסולי יוחסין קאי
BUT THE FIRSTMISHNAH<span class="x" onmousemove="('comment',' A collection of Halachoth the compilation of which began, according to Gaonic accounts, as early as Hillel and Shammai. When owing to political disorders many Halachoth of the Mishnah had been forgotten and their words had become a subject of controversy, the one Mishnah developed into many. This multiplication of Mishnahs occurred during the period of the later Beth Hillel and Beth Shammai. In order to avert the danger which threatened its uniformity a synod was convened in Jabneh to examine differences and to consider revision. But as the mass of material grew and with it the need for a methodical arrangement, R. Akiba undertook the task of sifting the material and editing it systematically in various sections (Sedarim) and treatises (Massekoth). J.E. vol. VIII, p. 610. ');"><sup>18</sup></span>