Footnote
a The code of Jewish traditional law known as the Mishnah specifies 39 major categories of work forbidden on the sabbath, along with numerous sub-categories. Among the forbidden activities were sifting, threshing, grinding and winnowing. (Tractate Shabbath 7:2) The Palestinian Talmud gives one rabbinical opinion of such forbidden work: ‘In case a woman rolls wheat to remove the husks, it is considered as sifting; if she rubs the heads of wheat, it is regarded as threshing; if she cleans off the side-adherences, it is sifting out fruit; if she bruises the ears, it is grinding; if she throws them up in her hand, it is winnowing.’