Our reading reminds us that signs and wonders do not work. In one of the Talmud’s most famous stories, Rabbi Eliezer tries to prove that his theory about the oven of Achnai is correct. He tries to do this with signs and wonders.

Rabbi Eliezer said to them: If the Halacha accords with me, let this carob tree prove it, whereupon the carob tree was uprooted from its place and moved one hundred amos. Unconvinced, the sages said to him you cannot bring proof from a carob tree. He then said to them: If the Halachah accords with me, let the water canal prove it, whereupon the water in the water canal flowed backward. The sages said to him: You cannot bring proof from a water canal. (Bava Metzia 59B)

Today we talk about why it is that signs and wonders never work. They never convince the unconvinced. Even the tenth plague—there was no home where a first born was not dead—persuades Pharaoh only temporarily. But he soon changes his mind and mobilizes his army and cavalry to pursue the Israelites at the Sea of Reeds. In the end, the Egyptians are never persuaded. They are defeated. They drown. We bring some learning from Sheila Heen, the head of the Negotiation Project at Harvard Law School, about why even the most powerful arguments and signs and wonders never convince the unconvinced.

And we talk about signs and wonders that do work and that we can believe in.