Can a non-Jew serve as a halachic agent for a Jew?
Halacha 1: The verse 'you shall offer, also yourselves' teaches that agents must be members of the covenant. A non-Jew can never serve as a halachic agent for a Jew, nor a Jew for a non-Jew.
Question 2
A father sends his minor son to a storekeeper for oil. The child loses both the oil and the payment coin. Who is liable?
Halacha 2: The storekeeper is liable because he gave items to a minor who cannot serve as a valid agent. The father sent the child only to convey the order; the storekeeper should have delivered with a mature adult.
Question 3
A broker was told to sell an item for no less than 100 zuz and sold it for 50. What must he do?
Halacha 6: A broker who violates price instructions must compensate the owner from his own pocket. Any profit beyond the authorized price, however, goes entirely to the owner.
Question 4
An agent disclosed he was acting for a principal but violated the principal's instructions. What is the effect on the transaction?
Halacha 4: When an agent disclosed his principal and then exceeded his authority, the transaction is nullified entirely and must be reversed, even if a kinyan (meshichah) was performed.
Question 5
An agent bought 400 barrels of wine with money entrusted to him; they all turned to vinegar. He claims they became vinegar after purchase. Does he need witnesses?
Halacha 9: The Sages ruled that 400 barrels turning to vinegar is a publicly known event. Since the claim is verifiable, the agent must bring witnesses to prove the wine was not vinegar at purchase — otherwise he must pay.