Siman 404

In the Gemara (43a) there is a doubt whether there are tkhumin above ten tefachim or not. And the reason for the doubt appears to be because there is no reshut harabim above ten, and likewise there is no karmelit above ten, as has been written in siman 345, and only a reshut hayachid ascends to the sky. And the majority of tkhumin are only in a reshut harabim and a karmelit, for a reshut hayachid—a place enclosed for a dwelling—is not within the measurement of the tkhum, as it is considered like four amot as has been explained; and if so, above ten, where there is neither a reshut harabim nor a karmelit, tkhumin do not apply there, or perhaps it is no different. And another reason for this doubt will be explained in section 7.

And behold, the Rambam in chapter 27, law 3, also wrote: "One who travels outside the techum above ten tefachim etc., it is a doubt whether there is techumin above ten or there is no techumin above ten." Thus far his words. And why did he not decide the law as is his custom? Because according to his view that twelve mil is from the Torah, there are techumin from the Torah and there are techumin of the rabbis of two thousand amot. Therefore, regarding twelve mil—it is a doubt regarding a Torah law and we rule stringently, and regarding two thousand amot—it is a doubt regarding a rabbinic law and we rule leniently. Therefore, the Rambam did not wish to elaborate on this, and so he wrote in a responsum. (Maggid Mishneh) And this is what our teachers, the authors of the Shulchan Aruch, wrote: "One who travels outside the techum above ten tefachim… it is a doubt… and that which is regarding a rabbinic law—its doubt shall be to rule leniently. However, if he was traveling… from within twelve mil to outside twelve mil—we follow the stringency, according to the one who says techumin of twelve mil is from the Torah." Thus far his words. And according to most poskim who do not hold of this rule of twelve mil—it is always to rule leniently.

The Tur wrote that there are techumin above ten [tefachim], because the Rosh wrote that this inquiry was not resolved—and we act stringently; see there. Many great authorities have already wondered about him, and there are those who answered that since this doubt remained for all the sages of the Gemara—therefore he was stringent. (Bach and Korban Netanel there). And I wonder about this, for this is well-settled regarding the matter of "the halacha follows the one who is lenient in eruv," for here there is no one who is lenient and the doubt is for everyone. But this is not relevant to "a doubt in rabbinic law is judged leniently," for in many places in the Shas, regarding an inquiry that was not resolved in a rabbinic matter, we follow the lenient path. And in my humble opinion, his reason appears to be because the Rif did not bring this inquiry at all, and if he had held it should be lenient—he should have brought it. But when he did not bring it—his silence is like his explanation that there are techumin. And their reason appears to be because in the Gemara there, they wanted to resolve that there are techumin from the Mishnah of "one whom they took out," where Rabban Gamliel and his colleagues came from the sea, and he said to them, "I was observing that we were within the techum before dark"—consequently there are techumin, for the sea is above ten [tefachim]. And they answered in the Gemara—that the ship was traveling in shallow water where the water is less than ten tefachim; see there. And the Rif and the Rosh hold that this is merely a rejection, and normally it is not so. Also from the Yerushalmi it is clear, for they explained the ship of Rabban Gamliel according to its plain meaning; see there, and so it is clear from the Rif. And I saw one who wrote that the opinion of the Rif appears to be lenient, (Beit Yosef in the name of Rabbeinu Yerucham) and I do not know from where he has this to say so. However, for the law, we hold like the majority of the poskim to be lenient and like the ruling of the Shulchan Aruch. (And what the Rif wrote in the first chapter of Shabbat, that was in the name of "there is one who says" and he rejected this for another reason; see there and examine it carefully.)

And more than this wrote our teacher, the Rema, that even if there is a doubt whether it is above ten or not—we follow the lenient view. Thus far his words. And even though in such a case there is a double doubt toward the stringent view, for perhaps it is below ten, and if you should say it is above ten—perhaps there are techumin above ten, nevertheless since it is a rabbinic matter and regarding an eruv—we are lenient even in such a case.

What is called "above ten tefachim," they explained in the Gemara there that this is, for example, if one jumped onto pillars that are ten high and their width is not four, or on one pillar of such height where part of it is within the techum and part of it is outside the techum. But a pillar ten high and four wide—this is not "above ten," and it is like solid ground; since it is comfortable for walking, it is considered like the ground. Similarly, high places such as roofs, mountains, and hills—this is not "above ten." However, it appears in my humble opinion, that if the mountain is very steep to the point that it is difficult to ascend it—it is also included in "above ten," according to the reasoning we wrote in siman 399, section 7, see there; and this requires further deliberation and needs investigation. (See Tosafot Shabbat 66b, end of the heading starting with "Kishurei")

And also regarding seas and rivers, it is proven in the Gemara that there is no prohibition of techumin if there are no techumin above ten. Since the water is ten deep—behold they are ten tefachim above the earth, and that is from the ground beneath the water. And one should not ask that if so, why did we explain in siman 397, section 13, that there is carrying outside the techum in water. But the truth is that this is a different matter, for there it is regarding the water itself, as they are all connected as one. And just as the water up to ten tefachim has techumin—so too the water above ten, for behold they are all connected as one. This is not the case for a ship sailing upon the surface of the water; since it travels only above ten—it has no prohibition of techumin, as it has no connection to the lower waters. (Tosafot 45b, s.v. 'liknu')

And the reason that there is no prohibition of techumin in seas and rivers even within twelve mil, the Rambam explained in the Responsa (siman 310). This is his wording: "Since they are a karmelit and carrying in them is only rabbinic, and it is not possible that one who transports over the surface of the water would be prohibited rabbinically, while one who walks would be lashed from the Torah." Thus far his words. And he further added a reason, that the twelve mil are corresponding to the camp of Israel, and this is not applicable in water; see there. And the explanation of his words is that since there it is certainly only rabbinic even within twelve mil, and beyond that is a rabbinic doubt and is ruled leniently. And behold, the first reason could also apply on land above ten handbreadths, for there one who throws above ten handbreadths—it is a mekom patur. And one should not ask that if so, we should say the same even within twelve mil, for one who transports above ten handbreadths is liable, as is found in Shabbat (92a), and as I wrote in siman 346 section 3.

And since there is no Torah prohibition of techumin in seas and rivers according to everyone for the reasons that have been explained, therefore one who arrived in a ship on Shabbat and reached the port—he may disembark and need not refrain, and he has two thousand amot in every direction, because he did not acquire a shevitah while being in the ship. However, this is specifically when the ship traveled more than ten [tefachim] above the water. But if it traveled lower than ten, meaning that from the floor of the ship to the ground is not ten tefachim, even though he is high up on the ship—he acquired shevitah there. And when he goes outside of two thousand amot from that place—his law is like one who went outside the techum, and he has only four amot. And if it is a doubt whether it was lower than ten or higher than ten—we follow the lenient view. And if he disembarked once after dark onto the dry land and returned and entered the ship, when he arrives at any place on Shabbat—he has only four amot, for he already acquired shevitah in the first place where he went out onto the dry land, and even if he went out after dark not at the time of the acquisition of shevitah. The general rule of the matter: Anyone who was on Shabbat for one moment on dry land or lower than ten in the water—there is his shevitah, and when he returned to the ship and it reached the port—it is forbidden for him to go outside of four amot, and if this occurred—he must wait there until night. However, if he is forced to go out of the four amot, such as if rains are falling or the sun is shining upon him and he cannot endure it, or if he needs to relieve himself and is forced to enter the city—the entire city is for him like four amot, for "since he entered—he entered," and the details of this law will be explained in siman 405 and siman 406, and there is no need to elaborate here. Only one must know, that in walking outside the techum like this—we consider him like one under duress and not like one who went out intentionally, as there are distinctions in this as written there. And the laws of entering a ship on Shabbat and on Erev Shabbat were explained above in siman 248 and in siman 339. (And see Magen Avraham, subsection 5)