Bava Metzia, Chapter 10, Mishnah 5. The Mishnah before us deals with three matters: a wall that fell into a friend's property, a worker whom the employer wishes to pay with goods, and the use a person makes of the public domain for his private needs.
A wall that fell into a friend's garden:
"Mi shehayah koslo samuch leginas chaveiro venafal" - A person whose wall was adjacent to his neighbor's courtyard, in which the neighbor was growing a vegetable patch, and the wall fell into the patch. This is how the law is conducted between them:
"Amar lo paneh avanecha" - The garden owner demands that the wall owner clear the stones and bricks from his garden, so that he can continue his work in the patch.
"Ve'amar lo higi'ucha" - The wall owner replies: The stones are worth a lot of money, take them for yourself and it will be a gain for you, while I am not interested in clearing them.
"Ein shomin lo" - We do not accept this claim. Once his wall fell into his friend's courtyard, the responsibility lies on him to clear it, and he cannot exempt himself from his obligation by declaring the stones ownerless to the neighbor.
All this is when the garden owner did not agree to the offer. But "mishekibeil alav" - if he said: It is acceptable to me, I actually need these stones and I will keep them - and afterward "amar lo: heileich es yetziosecha va'ani etol es sheli" - meaning the wall owner changes his mind and offers to cover the expenses of the clearing and take his stones back, because he feels that he lost out on the deal - "ein shomin lo". From the moment the neighbor accepted the offer, his courtyard acquired the stones for him through the acquisition of one's courtyard (kinyan chatzeir), and they belong to him completely; the first owner can no longer take them back.
Hiring a worker for straw and stubble:
"Hasocheir es hapoel la'asos imo beteven uvakash" - The employer hired a worker to clear his field and gather the straw and stubble, meaning the parts of the grain that have no kernels. Once the worker finished his work, "ve'amar lo: tein li sechari" - and he said to him: Give me my wages, the employer answered him: "Tol mah she'asisa bisecharecha" - Take all the straw that you gathered in exchange for your wages, since its value is greater than the wage for your work. And regarding this the Mishnah says: "Ein shomin lo", and it is incumbent upon the employer to pay the worker in coins.
And there is a novel ruling here: Generally, a debtor can repay his debt with movable property and goods - whether with a gold bar or with other objects - as long as he provides them against the value of the debt, and he is not obligated specifically to pay in cash. However, regarding a hired worker's wages the law is not so: The worker is entitled to demand his wages in actual coins, and the employer cannot force him to accept goods. Therefore, when the employer claimed, "Take the stubble against your wages", the worker can say: I do not agree to this, and you must pay me in cash.
But "mishekibeil alav" - if the worker accepted the offer and said: I will take the stubble, since its value is greater than the coins - and afterward "amar lo: heileich secharacha va'ani etol es sheli", that the employer changed his mind and wishes to return the stubble to himself and pay coins - "ein shomin lo". However, this is only the case when the worker made a formal act of acquisition, such as lifting the stubble, at which point it became his. As long as he did not make an act of acquisition through lifting (hagbahah), he did not acquire it, and the employer can still change his mind and pay him coins for his work's wages.
The difference between the two cases:
In the first case, of the stones that fell into the neighbor's garden, a person's property - his courtyard - acquires for him even without him doing any act, and therefore the garden owner acquired the stones immediately upon agreement. But in the matter of the worker, he does not acquire the stubble until he actually lifts it, and until then the employer is allowed to change his mind; and once the worker has made his acquisition, we no longer listen to the employer.
Using the public domain:
From here, the Mishnah moves to discuss a person who makes use of the public domain, in a public area - such as a dirt path passing through a village, where everyone has the right of way, and people wish to use it for their needs because they have nowhere else. One of the common uses was with manure: livestock owners who had excess manure would transfer it to farmers for fertilization, and the transfer was done by the livestock owner taking the manure out to the dirt path, and from there the farmer who wanted to fertilize his field would take it. Thus, they are making use of the public domain.
Is this permitted? The Mishnah permits this, but only with immediate removal: "Hamotzi zevel lirshus harabim - hamotzi motzi vehamzavel mezavel" - one who takes out manure to the public domain, the one taking it out takes it out and the one fertilizing fertilizes. The simple meaning of the text is that the one bringing it out brings it out and the one fertilizing fertilizes, and its intention is that the actions must be done one after the other at that exact time. There is no permission to leave the manure lying there for a period of time, taking up space in the public domain and causing a hazard for passersby; it is permitted to take it out there, provided that it is cleared away immediately on the spot.
It must be clarified: this permission concerns the right to use the public domain, but it does not exempt one from liability. If damage occurred - for example, his friend's animal passed by there at that time, slipped on the manure and was injured - the owner of the manure is liable for the damages, whether he is the original owner (when the buyer has not yet made an act of acquisition) or whether he is the new buyer who has acquired it. We find that there is a right of use here, and alongside it, full liability for damage.
Labors that take time:
What is the law regarding labors that last longer than a mere transfer? Regarding this, the Mishnah says:
"Ein shorin tit birshus harabim" - it is forbidden to soak clay in the public domain until it becomes mortar.
"Ve'ein lovnim levenim" - it is forbidden to place bricks in the public domain for the purpose of firing them, as this takes a long time and takes up space in the public domain, and a person has no right to do so.
"Aval govlin tit birshus harabim" - a brief use is permitted for the purpose of kneading the clay and preparing the mortar.
"Aval lo levenah" - however, one may not knead in the public domain for the purpose of making bricks, and even for the very mixing of the clay, because the work of making bricks takes a long time, and one may not take up space in the public domain for a prolonged period.
Building adjacent to the public domain:
One who builds a structure adjacent to the public domain is not building inside it, but he necessarily must enter it to place the bricks, set up his tools, and the like. Is this permitted? The Mishnah says: "Haboneh birshus harabim - hamevi avanim mevi vehaboneh boneh" - one who builds in the public domain, the one bringing stones brings them and the one building builds. The intention is not that he builds a wall inside the public domain itself, as it is not his, but rather that he stands in the public domain for the purpose of building his wall. And like the previous language, "the one taking it out takes it out and the one fertilizing fertilizes", here too: it is permitted to bring the stones into the public domain, provided that they are set in the wall immediately and swiftly. The bricks may not be left lying there overnight or the like; rather, the one bringing them brings them, and they are immediately built into the wall.
And even though he is permitted to be there temporarily - whether for the bricks, or for kneading the clay and placing the manure in the previous cases - if he caused damage, he is liable to pay. The very permission to be in the public domain does not exempt one from liability when a hazard occurs.
The opinion of Rabban Shimon ben Gamliel:
Rabban Shimon ben Gamliel disagrees on two points:
One who does building work on his property adjacent to the public domain may set up there with the bricks and tools for thirty days, and it does not need to be immediate.
Any place where he has permission to be, he is exempt from the damages that occurred, and he can say: I have permission to stand here, and passersby must be careful and watch where they are going.
The wording of the Mishnah is not explicit about all of this, but merely states that he is permitted to prepare his work thirty days in advance, meaning to arrange the bricks and the tools; the exemption from liability is not explicit in the Mishnah, but this is the halachah, as the Gemara explains.
Nevertheless, the halachah does not follow Rabban Shimon ben Gamliel: A person is not permitted to set up thirty days in advance in the public domain; and if he occupied the public domain for even a single minute with permission, and during that minute someone tripped over his belongings and was injured - even though he had permission to be there, he is obligated to pay for the damages caused by his belongings.