The Oven of Achnai

Rabbi Baruch Mordechai Ezrachi stood on the steps of the sanctuary before the assembled yeshivah and related the famous story of “The Oven of Achnai” (Bava Metzia 59b):1

During the era of the Tannaim, earthenware ovens were common, and multiple halachic discussions revolved around their halachic status.

One such discussion was about an oven that became ritually impure.2 In order to purify it from its impurity, they cut it into segmented rings and they later reconstructed it and placed sand between each segment. The question was whether it then reverted to being susceptible to impurity or not. Rabbi Eliezer’s opinion was that it could no longer contract impurity, whereas the Sages held that it could.

Now, one day a man entered the beit midrash where the sages of Israel were present at that time, and he asked a question:

“I have at home such an oven (with sand placed between each ring) which had previously become impure, and now that it was sliced into segmented rings, I baked in it. What is the status of the food—pure or impure?”

A heated halachic debate began in the study hall. Rabbi Eliezer steadfastly maintained his view that the oven is pure and consequently the food is pure, while the other sages held to their opinion that the oven is impure and therefore the food is impure.3

Rabbi Eliezer stood his ground and began to lay out complex arguments; with the immense power of his pilpul he “took mountains and ground them against each other” to prove his position. On that day, Rabbi Eliezer provided every answer in the world!

Yet the sages of Israel did not accept his reasoning.

Said Rabbi Eliezer to the sages: “If the halacha is in accordance with me, let this carob tree standing outside the study hall prove it!” No sooner had he finished speaking than the carob tree uprooted itself from its place and flew a distance of four hundred cubits.

They said to him, “One does not bring proof from a carob tree.”

He said to them, “If the halacha is in accordance with me, let the stream of water prove it!” Immediately, the stream flowing past the study hall began to run backward [i.e., it flowed from low ground to high ground].

They said to him, “One does not bring proof from a stream of water.”

He then said to them, “If the halacha is in accordance with me, let the walls of the study hall prove it!” The walls of the beit midrash inclined toward collapse.

Rabbi Yehoshua rebuked the forces of nature that displayed these feats, saying: “Torah scholars may be defeating one another in halacha, but what business do you have interfering?!”

Out of respect for Rabbi Yehoshua they did not fall, but out of respect for Rabbi Eliezer they did not straighten up, and they remained leaning.4

Rabbi Eliezer then said to them, “If the halacha is in accordance with me, let Heaven prove it!” A heavenly voice went forth and said: “What do you want with Rabbi Eliezer? For the halacha follows him in every instance!”

Rabbi Yehoshua stood up on his feet and declared: “Lo ba-shamayim hi!—‘[The Torah] is not in the heavens!’” (Deuteronomy 30:12)—Ever since the Torah was given at Mount Sinai, we pay no heed to a heavenly voice! It has already been written in the Torah at Sinai: “Acharei rabim le-hattot—After the majority must one incline” (Exodus 23:2). Thus, since we all disagree with Rabbi Eliezer, the halacha is not in accordance with him, and it is also not in accordance with the heavenly voice!

The halachic debate concluded. The sages of Israel turned to the person who had asked the question and said to him: “Go and bring the food you baked in that oven.” The man brought it, and the sages burned it before Rabbi Eliezer’s eyes—because that food was taharot (sanctified food items that must be kept ritually pure), and taharot that have become impure must be burned.

The Gemara continues and relates:

When Rabbi Natan later encountered Eliyahu the Prophet, he asked him: “What did the Holy One, blessed be He, do at that moment (when Rabbi Yehoshua and the sages refused to listen to the heavenly voice)?”

Eliyahu said to him: G-d smiled and said, “Nitzchuni banai, nitzchuni banai!—My children have defeated Me, My children have defeated Me!”

From that time on, the tale of this segmented oven was referred to as “the Oven of Achnai”—just as the way of the snake (achnai) is to rest with its body curled around and its tail in its mouth; so did the sages of Israel encircle Rabbi Eliezer with arguments from every side!

Wellsprings of Wisdom

1. Birkat Mordechai (Devarim, p. 161).
2. If an earthenware oven became impure (for example, if one of the eight crawling creatures fell into it), there was no way to purify it; it had to be broken. As it is said: “An oven or stove shall be smashed; they are impure” (Leviticus 11:35).
3. Rashi explains (Berachot 19a): “This involves an earthenware oven that is movable. It is formed initially from clay and fired in a kiln like other pottery. If it became impure, Scripture required it to be ‘smashed.’ If one smashed it in this way, by slicing it all around into circular rings, and then rejoined it with a cement of sand between each ring—Rabbi Eliezer declares it forever pure, for it is no longer considered an earthenware vessel since it was not fired in a kiln [after being reconstructed]. But the Sages declare it impure.”
4. Here is a point to ponder: When the walls of the study hall inclined to fall, Rabbi Yehoshua did not say, “One does not bring proof from the walls.” No! He instead rebuked them: “Torah scholars may be defeating one another in halacha, but what business do you have?!” Why did he not lodge a similar protest against the carob tree or the stream? Is the nature of those such that it “permits” them to stick their heads into a halachic dispute between sages?! Apparently, the “walls of the study hall” have a different way; they bear more relevance to what transpires within the walls. Those cannot simply be dismissed with “no proof is brought from them”...