Pinchas was hosting a group of friends at his house for a Melaveh Malkah get-together.
“Would you mind running out and buying three pizza pies?” Pinchas asked David. “There’s a store two blocks away, Pizza Plaza. I’ll pay you back.”
“Sure, no problem,” said David. He headed out.
“Is Pizza Plaza yoshon?” asked Aharon.
“Yes,” replied Pinchas. “Our family and some of our friends are careful to eat only yoshon.”
“But I heard that Pizza Plaza just changed hashgacha,” said Aharon. “You should check.”
Pinchas called the store. “We used to be yoshon,” the store replied, “but recently we changed hashgacha and no longer guarantee yoshon.”
Pinchas tried calling David to stop him, but he heard the phone ring in his living room. “David left his phone here,” he muttered.
“Please run after David and tell him not to buy there!” Pinchas said to Aharon. “You should be able to catch him. Buy from Pizza Palace instead, on the next block; they’re certainly yoshon.”
Aharon ran out after David to Pizza Plaza and caught him… just after he’d left the store.
“Pinchas said not to buy here because they’re no longer yoshon,” Aharon exclaimed.
“Too late,” said David. “The store won’t take the pizza back after I left.”
Aharon went on to Pizza Palace to buy three more pies, while David returned to Pinchas with the pizza in hand.
“I’m sorry for the mistake,” Pinchas said. “I’ll pay you whatever the pizza cost. Whoever wants can take the extra pizza home with them.”
“If it turned out to be a mistake that wasn’t your fault, I’m not sure you have to reimburse me,” replied David. “It was also my fault that I forgot my phone here.”
The two called Rabbi Dayan and asked:
“Is Pinchas required to reimburse David for the three pizza pies?”
“An agent who faithfully fulfills his task is considered as acting on behalf of his sender,” replied Rabbi Dayan. “Thus, his purchase is valid on behalf of the sender, who cannot retract afterwards even if the agent paid with his own money.” (B.K. 102b; Rema 102:1, 183:4; Gra 102:5).
Nonetheless, an agency that is in error is usually void, whether the error is on the part of the sender or the agent. Thus, one could argue that because Pinchas was mistaken about the hashgacha, the agency is void, so that David’s purchase of the pizza on his behalf is void.
Nonetheless, when someone lays out money with reliance on another person, that person is required to compensate him. This is essentially the concept of a guarantor (arev). When someone lends money with reliance on the guarantor, the guarantor is liable to compensate the lender if the borrower defaults (B.B. 176b; C.M. 129:2).
So too, here, even if the agency is void, David laid out money in good faith with reliance on Pinchas, and the money cannot be recouped by returning the pizza, so Pinchas is required to compensate David for what he laid out (Responsum Rashba 1:1006; Gra 102:5).
For this reason, the sender would be liable even if he asked a non-Jew to buy for him. Although a non-Jew is not halachically considered an agent, because he laid out the money with reliance on the Jew, the Jew is required to compensate him (B.M. 71b; Erech Shai 182:1; Pischei Choshen, Pikadon 11:8[21]].
Moreover, even though Pinchas explicitly cancelled the agency before witnesses (the other friends), since David was not aware and purchased the pizza as instructed, Pinchas is liable to reimburse David for what David laid out with reliance on him (Nesivos 182:3).
The fact that David forgot his cellphone in the house is also not reason to exempt Pinchas. (Perhaps it might be a factor regarding a professional courier service which would be expected to have customer service available.)
“Thus,” concluded Rabbi Dayan, “although it turned out that Pinchas sent David in error to buy from Pizza Plaza, and he even cancelled the agency before David bought the pizza, Pinchas is liable to reimburse David for what David laid out with reliance on him.”
Verdict: An agent’s actions are valid on behalf of the sender. Even if the agency is void – such as when it was in error, through a non-Jew, or was cancelled – the sender is liable to reimburse the agent for what the agent laid out with reliance on him.
