The Doubt That Ended and the Day That Stayed

The Hook

Four chapters of astronomy, and then this. Everything the Rambam has taught so far about sanctifying the month by sighting and adding a thirteenth month to the year, all of the reckoning and the witnesses and the interrogation about which direction the horns were tilted, belongs to the Sanhedrin in Eretz Yisrael, or to a court of ordained judges sitting in the Land with the Sanhedrin's authorization. Nobody else. And then the sentence that quietly closes the door: when there is no Sanhedrin in Eretz Yisrael, the months are established and the leap years fixed solely by the calculation we follow now. So the entire apparatus we have been studying is, at this moment, out of service.

The Rambam is not sentimental about it. It is a law given to Moses at Sinai, he says, that when there is a court, the calendar goes by sighting, and when there is no court, the calendar goes by the fixed reckoning, and the sighting is of no consequence at all. Of no consequence. You may walk outside tonight and see the new crescent with perfect clarity, and it means nothing about which day is Rosh Chodesh. That is a startling thing to say after four chapters of teaching a person how to look. And then the chapter turns to the second day of the festivals, which was invented because nobody knew what the court had decided, and rules that we keep it now, when everyone knows exactly what the calendar says, because our ancestors kept it.

Handed to a Court, and Then to a Calculation

The source is the verse spoken to Moshe and Aharon in Egypt, this month shall be for you the first of the months. The Oral Tradition, transmitted teacher to student from Moshe himself, reads those words as an act of entrustment: this testimony is handed to you and to those who will arise after you and stand in your place. Not to the sky. Not to the arithmetic. To a specific succession of people sitting in a specific land. The Rambam then tracks what happened when that succession failed. Through the Mishnah and on through the Gemara until Abbaye and Rava, the people relied on the establishment made in Eretz Yisrael. At the end of the Talmudic period, with the Land in ruins and no standing court left in it, all Israel took up the fixed calendar, and that is where we still are.

The fixed calendar is not a replica of the sighting. Sometimes the day it establishes is the day the moon is actually seen. Sometimes the sighting comes a day earlier, sometimes a day later. The Rambam notes that the calculated day falling after the sighting is an extraordinarily rare event and happens only in lands west of Eretz Yisrael. He mentions this without alarm, because on his own terms it changes nothing. The calendar is not attempting to describe the moon. It is standing in for a court, and a court was never a telescope either. A court was a room in which human beings said a word.

Which sets up the last halachah of the chapter, and it is the one worth carrying around. The calculations that we all make now, every person in his own community, to know which day is Rosh Chodesh and which day is Rosh HaShanah, do not establish anything and we do not rely on them. We do not intercalate years and we do not fix months outside the Land. We rely on the reckoning of the inhabitants of Eretz Yisrael and on their establishment of the calendar. Our own arithmetic is done only so that we should know, and what we are trying to know is which day the people in the Land have established. It is their establishing that makes the day a festival, not our calculating. Two Jews on opposite sides of the world can run the identical formula and get the identical answer, and only one of them is making a festival. The other is finding out about one.

The Day That Outlived Its Reason

Now the second day. When the Sanhedrin sat and the calendar ran on sightings, the people of the Land and everyone the messengers of Tishrei could reach kept one day of each festival. Those too far for the messengers kept two, because they genuinely did not know which day the court had chosen. That is a hedge against ignorance, and it is entirely reasonable. But in the present era, the Rambam writes, when the Sanhedrin is gone and the court of the Land establishes the months by the fixed reckoning, by law it would be appropriate for Jews everywhere to keep a single day, because the far reaches of the diaspora and the inhabitants of the Land are working from one and the same calendar. He says it plainly. By the logic of the law, one day. And then: nevertheless, the Sages ordained that they retain the custom of their ancestors.

So the rule becomes archaeological. Every place the Tishrei messengers would not have reached in the era when messengers were sent keeps two days now, exactly as it did then, and the people of Eretz Yisrael keep one, because they never kept two. The Rambam draws the conclusion without softening it: our celebration of the second festival day in the diaspora at present is a rabbinic institution. It is not a doubt. There is no doubt. It is a memory that has been given legal force.

Rosh HaShanah is where this gets stranger, because there the two days were never only a diaspora problem. Even when the calendar ran on sightings, most of the Land kept two days, since the messengers could not set out on the holiday itself and so nobody outside the courtroom knew. And even inside Jerusalem, where the court was sitting, there were many years with two days, because if no witnesses arrived on the thirtieth day, the day they had spent waiting was treated as holy and so was the day that followed. Since two days were kept even under the old system, the Sages ordained that everyone, including the inhabitants of the Land, keep two days of Rosh HaShanah now. And the Rambam again refuses to let it be mystified: even that second day is a rabbinic ordinance.

Ten Days From Jerusalem

Then he turns to the hard cases, and the chapter becomes a piece of forensic geography. The obvious move would be to make everything depend on distance, and the Rambam blocks it. Take a town five days' travel or less from Jerusalem, plainly reachable. We still do not assume the messengers went there, because we cannot know that they did. Perhaps no Jews lived there at the time. Perhaps Jews arrived only after the fixed calendar was already in use, in which case they are obligated in two days. Perhaps the roads were blocked, the way they were between Jerusalem and the Galilee in the time of the Mishnah, or perhaps the Samaritans would not let a messenger through. And if distance alone decided it, all of Egypt would keep one day, since Jerusalem to Egypt by way of Ashkelon is eight days' travel or less, and so would most of Syria.

The summary he gives is exact. More than ten days' travel from Jerusalem, two days, as was the custom, because the messengers could not be counted on to reach beyond ten days. Within ten days, look at what the place is. If it lies in the portions of Eretz Yisrael that Jews inhabited when the calendar ran on sightings after the second conquest, places like Usha and Shefaram and Luz and Yavneh and Nov and Tiberias, one day. If it is part of Syria, Tyre or Damascus or Ashkelon and the like, then follow the custom of your ancestors, one day if they kept one and two if they kept two. And if the place is Syria or the diaspora and has no inherited custom at all, or if it is a town newly built in the wilderness of Eretz Yisrael, or a city first settled by Jews in the present era, then two days, like the world at large. A brand new settlement inside the Land itself keeps two days. Not because anyone doubts the calendar. Because it has no ancestors in that place to inherit from, and the default of the world is two.

The Unifying Principle

The chapter is built on a distinction the modern mind resists: between knowing the right answer and having the standing to declare it. The Rambam has just spent four chapters teaching the astronomy so thoroughly that a diligent student could compute the molad in his own kitchen, and now he says the computation does not make a festival. Only an establishment does, and establishing is something a court in a particular place does, and when there is no such court we live off its stored instructions. The Sfat Emet loved to dwell on the blessing that calls God the One who sanctifies Israel and the seasons: the holiness of a festival is not weather arriving on schedule but something drawn down by a people who say the day is holy. That is what the Rambam is protecting. He would rather have Jews keeping a day whose original doubt has evaporated than Jews who believe their own correct arithmetic is what makes time sacred.

And this is why the custom is treated with such weight. The principle that a custom of Israel is itself Torah runs deep in the halachic tradition and the Alter Rebbe leans on it repeatedly, and the reason is visible here in its purest form. The second day is not a fence around a doubt anymore. It is the shape a people took when it was uncertain, kept after the uncertainty passed, and that shape now carries the memory of every generation that waited without knowing. To discard it because the reason expired would be to say that a practice is only ever worth its stated reason. The Rambam has already told us, at the end of Sefer Avodah a few days ago, what he thinks of a person who holds a law lightly because he cannot see the point of it.

The Baal Shem Tov taught that a person is wherever his will is, and that teaching does something specific to the last halachah of this chapter. A Jew in Yemen or Lithuania or Ohio runs a calculation whose only purpose is to discover what has been established in the Land. His arithmetic is an act of orientation, the way a man turns his body toward Jerusalem to pray. He is not generating the festival; he is locating himself inside one. And the Lubavitcher Rebbe returned constantly to the idea that exile is an assignment rather than an accident, that a Jew far from the center is not a diminished version of one who is near but a person sent somewhere with work to do. Read that way, the extra day is not a penalty for distance. It is the cost of drawing the same light into a place where it is not native.

Modern Application

Most of us live our religious lives in exactly the posture this chapter describes and we have never named it. We are extremely well informed and we have almost no authority. Every text is searchable, every calendar is on the phone, every question has been answered on some page, and it is very easy to slide from knowing the answer to believing that knowing is the whole of it. The Rambam says the sentence out loud so we cannot miss it: our calculations do not establish the calendar. Information is not jurisdiction. The person who can explain precisely why a thing is so and the person who is authorized to declare it so are doing two different jobs, and the confusion between them is the characteristic error of an age with unlimited access and thinning attachment.

The other application is about inherited practice that has lost its argument. Something in your family or your community is done for a reason that no longer holds, and someone eventually asks why we still do it. The honest answer is often the Rambam's: by strict logic we would not, and nevertheless the Sages ordained that they retain the custom of their ancestors. Notice that he disguises nothing. He tells you the reason has lapsed and the practice is rabbinic rather than biblical. He gives you every tool to dismantle it, and then rules that you keep it, because a people is not only a set of currently valid reasons. And the newly founded town in the wilderness of the Land, keeping two days with no ancestors to point to, is the sharpest form of the ruling. When you have no inherited custom of your own, you do not get to invent one from first principles. You take the practice of the world.

The Closing

There is something almost tender in the way this chapter ends the astronomy. The Rambam taught us to compute, and then told us that computing is only how we find out. He told us that seeing the moon now means nothing, that the second day answers a question nobody is asking anymore, and that a new town in the middle of Eretz Yisrael keeps the diaspora's practice because it has no grandparents there. None of it is about the sky. All of it is about the fact that time was handed to people, and the handing was the point.

You can run the calculation yourself and be right, and still not have made a single day holy. That is the whole chapter. The court establishes and the world finds out, and when the court is gone we keep finding out, and the day we keep for a doubt that ended two thousand years ago is not an embarrassment in the system but the proof of what the system was always about. Somebody said this day is holy, and everyone else spent the rest of history arranging their lives around what was said. Go outside tonight and look at the moon anyway. It will not tell you when the festival is. It was never supposed to.