Bava Basra, Chapter 5, Mishnah 9. The Mishnah before us discusses another case of selling oil, but its actual topic is different from the rest of the chapter. This is a difficult Mishnah to understand, so we will first introduce the background and the structure of the case. Only after we understand the main points will we return to the text of the Mishnah itself.
The Structure of the Case:
A child comes to the storekeeper holding a flask for oil and a coin, and asks for oil for his father worth half the amount he is holding. The main question that seemingly arises from the Mishnah is: Was the storekeeper permitted to fill the flask and send the child on his way with the jug of oil? After all, a minor is not a reliable agent. By the very act of sending the child, did the father say, "I am taking the responsibility upon myself," or not?
It is worth emphasizing: Had the father explicitly stated his wishes - in a note, or in prior notification to the storekeeper - there would be no room for discussion. In such a case, it is clear that the child is acting as an authorized agent, that the storekeeper must hand over the oil to him, and any mishap that occurs along the way will be the father's responsibility. However, our Mishnah deals with a storekeeper who did not receive such prior authorization. He handed the child the flask full of oil, and on the way home, the child broke the flask, lost the oil, and even lost the change he received.
Thus, the question is whether the storekeeper is liable, and the basis of the matter is as follows:
If the storekeeper was permitted to understand that the father is authorizing the child to act as an agent and bring the oil - the storekeeper is exempt.
If he should have understood that one does not hand over a jug of oil to be carried by a minor, who is not responsible as an agent - he should not have sent the oil in his hands, and since he did so, he is liable.
The Difficulty with the Liability for the Flask:
The Mishnah holds the storekeeper liable for the broken flask as well, and this is puzzling. After all, it was the father who sent his son with the empty flask in his hand. If indeed the minor is not responsible, then this is a deliberate loss: It is as if the father parted with the flask knowing full well that he would likely never see it again. If so, why should the storekeeper bear the responsibility for it breaking on the way? We can assume that he is liable for the value of the pondion - the oil and the money - which he should not have given to the child; but the flask is a different matter, and why should he be liable for it?
The Gemara's Answer - An Unauthorized Borrower:
The Gemara explains that the Mishnah contains a completely separate matter, a new and different dispute, even though it is not explicit in the text of the Mishnah: The child arrived with the flask in his hand, gave it to the storekeeper, and asked for the oil. He even gave him double the required amount, so he had to receive change as well. Before the storekeeper filled the flask, he used it for his own needs - "Here is a vessel of an exact measure before me, and I need to measure that exact amount for another customer, and I do not have a measuring vessel with me" - and he took it to measure with. This is an unauthorized borrower: one who borrows without the knowledge and permission of the owner of the item, since the father never gave the storekeeper the flask to use for his own needs.
What is the status of an unauthorized borrower?
According to the Tanna Kamma: He is like a robber. One who takes an item without permission is considered a robber and a thief, and his obligation is "he shall return the robbed item that he robbed" - what he robbed he must return to its rightful owner. Returning the flask to the child is not considered a return, since the child is not the owner but merely a child. Thus, the storekeeper, having become a robber, bears full responsibility for the flask until he returns it to its owner himself.
According to Rabbi Yehudah: An unauthorized borrower is not a robber. Even though borrowing without permission is not permitted and is improper, he is only a borrower. Although a borrower bears full responsibility, even in cases of unavoidable accidents and circumstances beyond his control, his responsibility ends when he returns the item to the place from which he took it. Once he returned the flask to the child, he ceased being a borrower and his liability for unavoidable accidents expired.
According to this, in a case where the shopkeeper made forbidden use of the flask brought by the child: according to the Tanna Kamma he becomes a robber, and is liable for unavoidable accidents until he returns the flask to its original owner - and its breaking by the child on the way home is an unavoidable accident, and therefore he is liable for it. However, according to Rabbi Yehudah he is nothing more than a borrower, and once he returns the flask to the child from whom he took it, his responsibility ends, and the breaking of the flask is not his responsibility. These are the foundations that make up the Mishnah.
Let us return to the text of the Mishnah:
"Hashole'ach es bno eitzel chenvani ufundyon beyado" - a person sends his son to the shopkeeper, and in his hand is not only the flask to bring the oil, but also a fundyon, which is worth two issars. The instruction is to fill one flask with oil, and the price of the oil is one issar - half the fundyon.
"Umadad lo be'issar shemen venasan lo es ha'issar" - the shopkeeper measured out for the child oil worth an issar, half a fundyon, and handed him the remaining issar as change. As mentioned, the Gemara explains that before handing the flask to the child, he used it for himself, and became a borrower without the owner's knowledge, and according to the Tanna Kamma, even a robber.
"Shavar es hatzluchis ve'ibed es ha'issar - chenvani chayav" - on the way home, the child shattered the flask and lost the money, and the shopkeeper is liable for everything: to replace the flask, the oil, and the money.
The details of the liability can be grouped into just two categories:
The flask - a matter preceding the sale itself, and the liability for it stems solely from the fact that the shopkeeper became a robber by using it without permission.
The oil and the coin - the value of the fundyon that the shopkeeper received from the father through the child.
The reason for the liability according to the Tanna Kamma:
According to the Tanna Kamma, and this is how the halachah is recorded in the Shulchan Aruch, the shopkeeper was expected to understand that one does not hand a flask full of oil to a child, who is not a reliable messenger. His understanding should have been that he should set aside the oil, and the father or a responsible adult messenger would come to collect the flask and the change. Once he returned the flask full of oil to the child with the change in his hand, he acted with complete recklessness. (And Rabbi Yehudah argues on this very principle.)
As for the money: the fundyon handed to the child was indeed like a deliberate loss, as if the father parted with it in advance and did not expect to see it again. However, in the meantime, the shopkeeper is in possession of a coin belonging to the father, and he is obligated to return it to him - under the laws of returning a lost object. Even if the father parted with it, the shopkeeper holds something belonging to the father, and handing it to the child is irresponsible. Therefore, the shopkeeper must return the fundyon or its financial equivalent - the oil and half the fundyon, the remaining issar - since he took the father's money, and that lost object was entrusted in his hands. This is the reason for his liability for both components: the value of the fundyon and the shattered flask.
The opinion of Rabbi Yehudah:
Rabbi Yehudah exempts: "Al menas ken sholcho" - the very fact that the child appeared with the money and the flask in his hand indicates that he was expected to serve as the delivery messenger, and this is an implicit authorization. Therefore, the shopkeeper is not responsible, neither for the money nor for the flask, and for two different reasons:
For the money and the oil - he is not responsible, since he gave them to the child with an implicit understanding derived from the child's very appearance, and this is the father's wish.
For the flask - even though he laid a hand on it, acting as an unauthorized borrower and borrowing without permission, he returned it to the child, and therefore ceased to be a borrower and his responsibility ended.
Conclusion of the Mishnah:
"Umodim Chachamim bizman shehatzluchit beyad tinok umadad chenvani letochah, shechenvani patur" - the Sages, who are the Tanna Kamma, agree with Rabbi Yehudah in a case where the shopkeeper did not use the flask for his personal needs at all. Since he did not become a robber, he bears no responsibility. Therefore, even according to them, if the child returned holding a flask full of oil, broke the flask, and lost the money - for the flask itself, the physical vessel, the shopkeeper is not liable.
However, regarding the oil and the money that were lost, with the value of a pundiyon, he is still liable according to the Tanna Kamma, and exempt according to Rabbi Yehudah - and the halachah follows the Tanna Kamma, the Sages.