Siman 352

The Rambam wrote at the end of chapter 15: "One who reads a scroll in a karmelit, and part of the scroll rolled into the public domain while part of it is in his hand—if it rolled beyond four amot, he turns it over onto the writing and leaves it, as a decree lest it slip entirely from his hand and he carry it four amot. If it rolled within four amot, he rolls it back to himself; and so too if it rolled into a private domain, he rolls it back to himself. If he was reading in a private domain and it rolled into the public domain, if it came to rest there, he turns it over onto the writing; and if it did not come to rest, but rather was suspended in the airspace of the public domain and did not reach the ground, he rolls it back to himself." Thus far his words.

The explanation of his words: Their books were made in a scroll like our Sefer Torah, and if one was reading in a karmelit, such as reading on an eskupa that is four wide and not ten high—if its second end rolled into the reshut harabbim at a distance of four amot, even though if he returns it now to himself there is no carrying of four amot in the reshut harabbim, for the first end is in his hand and there is no carrying of the entire book, nevertheless they forbade returning it, due to the concern that perhaps it will entirely slip from his hand and he will return it to himself, and there would be carrying of four amot in the reshut harabbim. But within four, where even if it entirely slips from his hand it would only be carrying from a reshut harabbim to a karmelit—they did not decree when the first end is in his hand, because of the disgrace to holy writings. But other items—it is forbidden even in such a case. (Maggid Mishneh in the name of the Rashba) And what should he do when he cannot return it to himself—he should turn it over onto the writing, so that it is not cast in such disgrace. But if it rolled into a reshut hayachid—it is permitted, even beyond four amot, for in a reshut hayachid there is no distinction. But if he was reading in a reshut hayachid, such as an eskupa that is ten high and four wide, or if he sat in his house or in his courtyard and it rolled into the reshut harabbim—even within four amot he turns it over onto the writing, for from domain to domain one does not need four amot, and there is no permission to return it to himself, unless the second edge has not yet come to rest on the ground but is hanging in the air, for then he rolls it to himself, as in such a case where there is no resting at all, even if it entirely slips from his hand he would not be liable. And also beyond four amot in such a case—it is permitted, and we do not decree lest it entirely slip from his hand and come to rest on the ground, for we do not enact two decrees. And it appears that when it has not come to rest, it is permitted even with other objects.

The Rosh and the Tur wrote that when its first end is in his hand, even if it rolled outside of four amot in the reshut harabim while he is reading in a reshut hayachid—he may roll it to himself when he is reading in a low place such as on an iskupa, even if it is ten high and four wide; nevertheless, since the reshut harabim passes before it and it is dragged in a place where many people tread, they did not decree regarding sacred writings in such a case, due to the disgrace of sacred writings. And the Tur further wrote: "If he was reading it on the roof, and its one end rolled from his hand, as long as it has not reached the lower ten tefachim close to the ground—he may roll it to himself. If it reached the lower ten tefachim, if the wall is sloped in a manner that it rests upon it—it is forbidden to roll it to himself, and so that it does not remain in disgrace, he turns it over on the writing. And if it is not sloped—as long as it has not reached the ground, he may roll it to himself." Thus far his words. And this is when the sloped wall is a reshut harabim, such as where many people shoulder burdens upon it. But if many do not shoulder burdens upon it, such that it is a karmelit—he may roll it to himself. (Bach) And when it has not reached the lower ten, even if it rests on a sloped wall—he may roll it to himself, for it is a mekom patur. (ibid.) And in this law the Rambam does not disagree, rather he shortened the language, and the intention is one, and they only disagreed in the previous law. And our teachers, the authors of the Shulchan Aruch, wrote without specification according to the opinion of the Tur for leniency, see there. (Because the opinion of the Rif is also such, as the Beit Yosef wrote, see there; and in our books these laws are not relevant at all, as is understood, for it is not the way to read from a Sefer Torah alone).