Jewish law was strict, and this caused a constant, though largely unrecorded, leakage into the host communities, but it was the discipline which also kept the Jews together and their heads high. Sabbath (root-verb shabath) meant to cease. All work was forbidden, Exodus specifically prohibiting kindling a fire and the Mishnah listing thirty-nine categories of labour used in making it. The Oral Law principle of erecting ‘fences round the law’, to prevent even accidental breaches, spread the area of prohibition still further.
