The sages were debating whether a certain oven, built in sections and joined with sand, could become ritually unclean. Rabbi Eliezer ruled it pure. The majority ruled it impure. He answered every argument they raised, but they would not move.
Finally, Rabbi Eliezer turned to them and said, "If the law is as I say, let this carob tree prove it." The tree uprooted itself and flew a hundred cubits through the air, some say four hundred. The sages shrugged. "We do not accept evidence from a carob tree."
"Let this stream prove it," he cried. The water in the channel reversed and ran uphill. "We do not accept evidence from a stream," they said.
"Let the walls of the study house prove it." The walls of the beit midrash began to topple inward. Rabbi Joshua stood up and rebuked them. "If scholars are disputing a point of law, what business is it of yours? Be still." Out of honor to Rabbi Joshua, the walls did not fall. Out of honor to Rabbi Eliezer, they did not straighten. They remain tilted to this day.
Rabbi Eliezer played his last card. "Let Heaven itself prove it." A bat kol, a voice from above, rang out: "Why do you argue with Rabbi Eliezer, when the law follows him in every case?"
Rabbi Joshua rose to his feet, quoted Deuteronomy, and called back to the sky, "It is not in heaven" (Deuteronomy 30:12). The Torah was given at Sinai, and Sinai itself wrote the rule we now follow: "After the majority you shall incline" (Exodus 23:2). A heavenly voice no longer overrules a human court.
Later, the prophet Elijah appeared to Rabbi Nathan. Nathan asked, "What was the Holy One doing at that moment?" Elijah answered, "He was laughing and saying, 'My children have defeated Me. My children have defeated Me'" (Bava Metzia 59b).
God delighted in losing the argument, because it was exactly the kind of argument He had raised His children to win.