018 - הִלְכוֹת קִדּוּשׁ הַחֹדֶשׁ פֵּרֶק יח

Laws of Sanctifying the New Month, Chapter 18

1. It is a known and clear matter that if the calculation shows that the moon should be visible at night, it is possible that it will be seen, and it is possible that it will not be seen because of clouds that cover it; or because the location is a valley, or there is a high mountain to the west of the people of that place, so that it is as if they are sitting in a valley: for the moon will not be visible to someone in a low place, even if it is large, but it will be visible to someone standing on the top of a high and steep mountain, even though the moon is very small; likewise, it will be visible to someone dwelling on the seashore, or to someone traveling by ship on the great sea, even though it is very small.

2. Similarly, in the rainy season, if the sky is clear, the moon will be seen more than it is seen in the summer season: because in the rainy season, if it is clear, the air is much purer and the sky appears with greater clarity, since there is no dust mixed in the air. But in the summer season, the air is as if smoky because of the dust, and the small moon will not be seen.

3. Whenever you find that the arc of visibility and the initial elongation, when measured precisely with both their endpoints, are minimal, the moon will be very small and will only be visible in a very high place. But if you find that the arc of visibility and the initial elongation are much greater, and several degrees have been added to the ends of their limits, the moon will appear large; and according to the length of the arc and the initial elongation, so will be its size and its visibility to all.

4. Therefore, it is proper for the Beis Din to keep these two matters in mind—namely, the time of visibility and its location; and they ask the witnesses: in what place did you see it? For if the arc of visibility is short, and the calculation indicates that it will be seen only with difficulty, for example, if the arc of visibility was nine degrees and five parts, and the initial elongation was thirteen degrees exactly, and witnesses came who saw it—if it was in the summer season, or in a low place—they are to be suspected, and examined thoroughly; but if it was in the rainy season, or in a very high place, it is certain that it could be seen, unless there were clouds separating.

5. If witnesses saw the new moon at its proper time and came and testified, and the Beis Din accepted them and sanctified this first month, and they counted twenty-nine days from the sanctified day, and on the night of the thirtieth the moon was not seen—either because it was impossible for it to be seen, or because clouds covered it; and the Beis Din waited for it all day on the thirtieth as we have explained, and no witnesses came, and they made the month full, and it turned out that the day of Rosh Chodesh of the second month was the thirty-first day, as we have explained.

6. And they began to count twenty-nine days from the day of Rosh Chodesh of the second month, and on the night of the thirtieth the moon was not seen—if you would say that they should make this Rosh Chodesh full as well and make it thirty days, and set Rosh Chodesh of the third month on the thirty-first day: it is possible that the moon will not be seen on the night of the thirtieth of this month as well, and so they would continue making months of thirty after thirty all year long; and it could happen that in the last month, the moon would be seen on the night of the twenty-fifth or the night of the twenty-sixth, and there is nothing more absurd and damaging than this.

Laws of Sanctifying the New Month, Chapter 18

7. Do not say that this matter is something uncommon—that the moon will not be seen at all during the year. Rather, it is something quite frequent, and this and similar occurrences happen many times in countries where the rainy season is long and there are many clouds. For we are not saying that the moon will not be seen at all during the year, but rather that it will not be seen at the beginning of the months; it will be seen later in the days that follow. Sometimes, it will not be seen because it is impossible for it to be seen; and in months when it is possible for it to be seen, it will not be seen because of clouds, or because it was extremely small and no one intended to look for it.

8. Rather, the tradition in the hands of the sages, passed down from person to person from Moshe Rabbeinu, is as follows: When the moon is not seen at the beginning of the months, month after month, the Beis Din establishes a full month of thirty days, and a deficient month of twenty-nine days. And so they calculate and establish full and deficient months—by fixing, not by sanctification, for they only sanctify based on sighting. Sometimes they make two full months in a row, or two deficient months in a row, as it appears to them from the calculation.

9. They always intend in their calculation that if the moon will be seen in the coming month, it will be seen at its proper time or on the night of its completion, but not before its time, which is the night of the twenty-eighth. And through these calculations of the sighting that we have explained, it will become clear to you and you will know when it is possible for the moon to be seen and when it is not possible for it to be seen; and on this basis they rely and make a month full after a month full, or a deficient month after a deficient month. And there are never fewer than four full months in a year, and never more than eight full months. And also, for the intercalation of these months that they intercalate according to calculation, they make the meal of the intercalation of the month, as we mentioned in the third chapter.

10. Whenever you find in the Talmud statements that show that the Beis Din relies on calculation, and that from Moshe at Sinai it was handed down to them, and the authority is in their hands to make a month deficient or full, and likewise that Rabbi made nine deficient months in a year, and all similar cases—everything is based on this principle, in a time when the new month was not seen at its proper time.

11. And so, when the sages said that they intercalate the month for a need, it refers to these months that they intercalate according to calculation, making one full and one deficient; and they are permitted to make a full month after a full month, or a deficient month after a deficient month. This is what it means to intercalate for a need—because the moon was not seen at its proper time. But when the moon is seen at its proper time, which is the beginning of its appearance after it has separated from the sun, they always sanctify, and it is impossible to delay or intercalate.

12. All these matters apply when there is a Beis Din and they rely on the sighting; but in these times, we rely only on the fixing according to this intermediate calculation, which is well known among all Israel, as we have explained in these laws.

13. It is explained in the books of astronomical calculation and gematrios that if the moon is seen in Eretz Yisroel, it will be seen in all the countries of the world that are to the west of Eretz Yisroel and are aligned with it. And if the calculation shows that it will not be seen in Eretz Yisroel, it is possible that it will be seen in other countries that are to the west of Eretz Yisroel and are aligned with it. Therefore, if the moon is seen in a country that is to the west of Eretz Yisroel, this is not proof that the moon was seen in Eretz Yisroel.

14. But if the moon is not seen on the mountaintops in the western country that is aligned with Eretz Yisroel, it is certain that it was not seen in Eretz Yisroel.

15. Similarly, if the moon is not seen in Eretz Yisroel, it is certain that it will not be seen in any of the countries to the east of Eretz Yisroel that are aligned with it. But if it is seen in Eretz Yisroel, it is possible that it will be seen in the eastern countries, and it is possible that it will not be seen. Therefore, if it is seen in a country that is to the east of Eretz Yisroel and aligned with it, it is certain that it was seen in Eretz Yisroel. But if it is not seen in the eastern country, this is not proof, for it is possible that it will be seen in Eretz Yisroel.

16. All these matters apply when the countries to the west and to the east are aligned, such as when they are situated between thirty degrees north and thirty-five degrees north. But if they are situated further north than this or less, they have different rules, for they are not aligned with Eretz Yisroel. And all these things that we have explained regarding the cities of the east and the west are only to clarify all the laws of sighting, to expand and glorify the Torah—not so that the people of the east or the people of the west should rely on the sighting of the moon, or that it should be of any benefit to them. Rather, they should always rely only on the sanctification by the Beis Din in Eretz Yisroel, as we have explained several times.