Great Regulars: And yet there is a tradition,

the Talmud acknowledges, that the Messiah will not arrive on Shabbat; and the sages are very reluctant to challenge what seems to be merely a folk belief, on the grounds that if so many Jews believe something, it stands a good chance of being true.

If it's not because of the techum, then, how can we be so sure that the Messiah will not come on Shabbat?

from Adam Kirsch: Tablet: When Messiah Is an Afterthought

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