The Hour We Cannot Know

Rabbi Eliezer and the Crisis of Sacred Time

Normally, I write about AI and learning. Today, I’m sharing a piece about time and how I read the opening of the Talmud, inspired by a conversation I had with Virgil.

This is how the Talmud begins:

MISHNA: From when, that is, from what time, does one recite Shema in the evening? From the time when the priests enter to partake of their teruma. Until when does the time for the recitation of the evening Shema extend? Until the end of the first watch. The term used in the Torah (Deuteronomy 6:7) to indicate the time for the recitation of the evening Shema is beshokhbekha, when you lie down, which refers to the time in which individuals go to sleep. Therefore, the time for the recitation of Shema is the first portion of the night, when individuals typically prepare for sleep. That is the statement of Rabbi Eliezer. The Rabbis say: The time for the recitation of the evening Shema is until midnight. Rabban Gamliel says: One may recite Shema until dawn. (Brachot 2a)

The Talmud opens with a simple question: “From when do we say the evening Shema?” (Brachot 2a)

Rabbinic literature begins with a discussion of time and timing, and an implicit philosophy of time. To open the Talmud is to be thrown into the world of time-keeping. Time is the ultimate catalyst.

The Written Torah begins with “In the beginning of…” (Genesis 1:1) but the Oral Torah, a living, evolving body of Torah commentary, gestures at a desire to get more clear on what happens after the beginning. It marks what Heidegger calls a “second beginning.”

To be on earth is to keep time. The fixing of the hours of one’s day both expresses and conceals the anxiety that Heidegger called finitude. We can calculate the hour of obligatory prayer, but not the hour of our death.

This temporal anxiety reverberates throughout Talmudic literature, most powerfully in Rabbi Eliezer’s teaching about death's unknowable timing: “Repent one day before your death.” (Shabbat 153a) When his students protest the impossibility—who knows when they will die?—he doubles down: “All the more reason to repent today, lest you die tomorrow.” The same sage whose opinion opens the Talmud, and ties evening Shema to the hour of the priests eating teruma here insists on daily spiritual preparation precisely because ultimate timing remains hidden from human calculation.

What emerges is a distinctly rabbinic poetics of time-keeping, one that negotiates between the human need for temporal structure and the profound uncertainty that shadows all mortal scheduling. The Talmud’s opening question about prayer timing and Rabbi Eliezer’s meditation on death timing follow the same logic: temporal humility before the unknowable.

Rabbi Eliezer’s approach to Shema timing reveals a fundamentally different relationship to temporality than what modernity has taught us to expect. When he says evening prayers should begin “when the priests enter to partake of their teruma,” he’s not providing a schedule; he’s anchoring prayer time to a habitual, embodied tempo. The priests’ meal wasn't scheduled for 7:43 PM. It happened when it happened, when purification was complete, when the sacred and everyday finally aligned. This is what Martin Heidegger would recognize as authentic temporality—time experienced through meaningful engagement rather than measured by external standards. Not that the time was arbitrary; it was definitely in the evening; but the core point is that, for Rabbi Eliezer, the timing of Shema is a first derivative of the activity of priests, and only secondarily a derivative of the movement of the night sky.

This priestly temporality carries special significance for Rabbi Eliezer himself, who descended from a priestly line. His temporal intuitions aren’t merely theoretical but genealogical, embodied in familial memory of when sacred timing actually governed daily life. The same rabbi who appeals to priestly meal timing for Shema would later be excommunicated in the story of tanur shel Akhnai precisely because his metaphysical realism—his insistence that divine truth exists independently of human consensus—clashed with the emerging rabbinic commitment to majority rule and human interpretation. Not incidentally, Rabban Gamliel, whose view is also featured in our Mishna, was known for his authority over the Jewish calendar, and his ability to to declare the new month, a victory of nominalism (“it’s a new month when I say it is”) over realism (“the new month is an objective reality out there we must uncover.”)

In that famous passage, Rabbi Eliezer calls down miraculous signs to support his halakhic position: a carob tree sprouts up, walls crumble, and finally a heavenly voice declares his correctness. But Rabbi Joshua responds with devastating finality: “It is not in heaven”—the Torah has already been given to human interpretation, and heavenly voices no longer determine Jewish law. The majority rules against Rabbi Eliezer, and he is banished from the academy. The first named speaker in the Talmud meets a tragic end, and so, too, his view of time.

The connection between these two passages reveals something profound about the nature of temporal authority. Rabbi Eliezer’s priestly timing for Shema represents the same metaphysical realism that would ultimately lead to his excommunication. Both his temporal philosophy and his interpretive method appeal to transcendent authorities—priestly rhythms, divine signs—that exist independently of human consensus or mechanical measurement.

But the Rabbis offer something radically different in both cases: “until midnight” for prayer timing, majority vote for halakhic interpretation. Here we encounter what Henri Bergson distinguished as “mechanical time”—abstract, measurable, divorced from lived experience. Midnight isn’t when anything sacred happens; it’s simply when the celestial clock strikes twelve. It’s efficient, practical, universal, and it makes sense when you’re living in diaspora and no longer have a temple; the loss of the temple was also a loss of a certain relationship to time. Anyone anywhere can know exactly when midnight arrives.

Heschel says that for Jews Shabbat is a cathedral in time, but glosses over the critical distinction between time as measured from the outside and time as lived from the inside.

The shift from Rabbi Eliezer’s priestly timing to the Rabbis’ midnight deadline represents more than practical adjustment—it marks a fundamental transformation in how human beings experience temporality itself, parallel to the shift from charismatic to institutional authority that defines the transition from Temple to rabbinic Judaism. Rabbi Eliezer’s time is eventful, connected to sacred simultaneity; the Rabbis’ midnight is durational, measured by human convention.

This parallels what contemporary philosopher Byung-Chul Han diagnoses as the loss of “lingering”—the capacity to dwell within meaningful temporal rhythms rather than constantly measuring duration. Rabbi Eliezer’s priestly time was lingering time; the Rabbis’ midnight represents measuring time. Yet the historical context makes this shift tragically necessary. The Mishnah was compiled after the destruction of the Second Temple in 70 CE, when the entire sacrificial system had been lost.

The priests that Rabbi Eliezer references were no longer offering sacrifices. Their teruma consumption had become a phantom limb of Jewish temporal experience. The Rabbis’ midnight represents not just practical convenience but necessary adaptation: How do you maintain religious discipline when the phenomenological anchors have been destroyed?

The Talmud's opening “mei’eimatai”—from when?—announces a temporal anxiety that echoes throughout rabbinic literature.

Rabbi Eliezer’s teaching about death timing illuminates the deeper structure of this anxiety. His students’ question—”Does a person know the day he will die?”—parallels the underlying anxiety of “mei'eimatai korin et Shema.” Both questions expose the fundamental tension between human need for temporal structure and the radical uncertainty that governs ultimate timing.

Rabbi Eliezer’s response creates what we might call a poetics of preparedness. Since we cannot know when death will come, we must live as if it could come today. Since we cannot master ultimate timing, we must find ways to live authentically within temporal uncertainty.

Rabban Yoḥanan ben Zakkai said the following story as a parable to this lesson: The situation is comparable to a king who invited his servants to a feast and did not set a time for them to come. The wise among them adorned themselves and sat at the entrance to the king’s house. They said: Is the king’s house missing anything necessary for the feast? Certainly the king could invite them at any moment. The fools among them went to attend to their work and said: Is there such thing as a feast without the toil of preparing for it? While the feast is being prepared, we will attend to other matters.

Suddenly, the king requested that his servants come to the feast. The wise among them entered before him adorned in their finest clothes, and the fools entered before him dirty. The king was happy to greet the wise ones and angry to greet the fools. The king said: These wise servants who adorned themselves for the feast shall sit and eat and drink, but these fools who did not adorn themselves for the feast shall stand and watch. There is a similar outcome for people who think that their day of death and judgment is far away and do not prepare themselves for it. (Shabbat 153a)

Rabban Yochanan ben Zakkai’s parable of the kings feast extends this poetics into social space. The wise servants dress for the banquet without knowing when it will begin; the foolish ones assume they have time to attend to other matters first. The wise live in what Heidegger would call “anticipatory resoluteness”—readiness for the moment that cannot be predicted but must be prepared for.

What Rabbi Eliezer was trying to preserve through his priestly reference point was sacred simultaneity, the sense that individual prayer participates in a larger cosmic rhythm. When Jews said Shema at the moment priests consumed teruma, they weren’t just reciting words; they were joining an ongoing sacred performance that connected earth to heaven. The Rabbis’ midnight abandons this simultaneity for something else: universal accessibility.

The Talmudic sages couldn’t have anticipated Instagram or Slack notifications, but they were grappling with the same fundamental question: How do we maintain meaningful relationship to time when traditional rhythms have been disrupted?

The first page of the Talmud, read through the lens of Rabbi Eliezer’s death teaching and his later excommunication, becomes a meditation on one of our most pressing contemporary questions: Is it possible to live meaningful lives within the temporal structures that modern society requires? Can we preserve forms of deep time—seasons, rhythms, embodied practices—while participating in the coordinated time that makes complex societies possible?

The Talmud begins with a question about timing because being human means being temporal, caught between the need for structure and the reality of uncertainty, between mechanical measurement and meaningful moment. The sages’ multiple answers suggest that the goal isn’t to resolve this tension but to live gracefully within it, prepared for both a predictable schedule of day to day task management and an unpredictable life of dwelling poetically on this earth.