Yerushalmi Eruvin 7:3 ירושלמי עירובין ז׳:ג׳

MISHNAH: If a ditch between two courtyards is ten [hand-breadths] deep and four wide, one makes two eruvin but cannot make one eruv even if it is full of straw or provender. If it is full of dust or pebbles, one makes one eruv but cannot make two eruvin⁵A ditch 10 hand-breadths deep and 4 wide from wall to wall is treated as if it were a wall more than 10 hand-breadths high. If the ditch is used for storage but contents will be removed and used in the foreseeable future, it remains a separation for the rules of the Sabbath. But if it is filled with material which probably will not be removed, it does not divide from the moment that the actual ditch is no longer 10 hand-breadths deep..

HALAKHAH: Paragraph. ⁵⁶Commentary on Mishnah 3. The text is taken from a discussion of the impurity of the dead, Nazir 9:2 Notes 79–87, Pesaḥim 7:7 34d l. 27. Therefore straw to be disregarded cannot be disregarded. Does the Mishnah not follow Rebbi Yose, since Rebbi Yose said, straw said to be disregarded is disregarded⁵⁷This refers to the rules of the tent-impurity caused by a corpse. A “tent” is any covered space in which there is at least one hand-breadth of space between the corpse and the roof. If the space is enclosed, the impurity is restricted to the “tent”; anything above the ceiling and below the floor of the “tent” is pure. But if the entire space between floor and ceiling is filled with matter, there is no tent and the impurity extends indefinitely above and below the tent space. This is known as “squeezed impurity” (Mishnah Ahilut 15:1,5,6). It is implied in Tosephta Ahilut 15:5 that R. Yose restricts “squeezed impurity” to material permanently deposited; but a storage of straw which is to be removed in the future is not counted as filler.? Rebbi Yose ben Rebbi Abun in the name of Rav Ḥisda: It is everybody’s opinion. What Rebbi Yose said, if he mixed it with dust⁵⁸Not really “mixed with”, but “treated like,” as formulated in the Tosephta.. “There is straw which is treated like dust and dust which is treated like straw. Straw not to be removed is like dust; dust to be removed is like straw.⁵⁹Statement of R. Yose in Tosephta Ahilut 15:5; quoted in Eruvin 79a. “Straw” stands here for “material to be removed,” “dust” for “permanent filling.”” In the House of Rebbi Yannai they said: If he covered it with mats it is disregarded. Come and see: If he filled it with mats it is not disregarded⁶⁰Since the filling can easily be removed, the ditch still separates., if he covered it with mats it is disregarded⁶¹If a ditch is filled with any material, even straw, but this is covered with mats to create a floor from one side to the other, the courtyards become one and require one eruv. Šabbat 100a.. If he filled it with branches of date palms it is problematic⁶²No ruling is available in this case.. Rebbi Zeriqan, Rebbi Immi, in the name of Rebbi Simeon ben Laqish: Even thin sheets⁶³This translation is tentative; it follows the Pesaḥim text, reading רַק. Neither the text here רוֹק “spittle” nor the one in Nazir רֵיק “emptiness” are appropriate..