Kalman approached his neighbor, Dov, on Sunday afternoon. “My parents are coming to visit from overseas tomorrow and are leaving next Sunday morning,” he said. “We don’t have enough room in our car for the whole family. Could we rent your mini-van for the week?”

After some back-and-forth, Dov agreed to rent Kalman his mini-van for $300.

“Also, do you have a roof luggage rack we can borrow during that time?” asked Kalman.

“Yes,” said Dov. “I’ll leave it with the car.”

Later that week, on Friday afternoon, Dov called. “Please return the car keys on Motozei Shabbos,” he said. “We have a bris on Sunday morning and we’re all going. We also need the roof luggage rack.”

“But we rented the car for a week,” said Kalman. “I was planning to drive my parents to the airport on Sunday in your mini-van.”

“We never agreed to rent the car for Sunday,” said Dov. “You just asked to rent it for this week.”

“That’s not true,” said Kalman. “I told you that I wanted the car through Sunday.””

“That’s not how I remember it,” said Dov. “We didn’t include Sunday. Can’t you take your parents to the airport in your car?”

“With them and the luggage, we’d only have room for one other person,” Kalman replied. “We’d all like to go and say good-bye. It’s not like we get to see them often. Can’t your family fit in your other car for the bris?”

“It will be extremely tight, and the kids will go crazy,” said Dov. “It’s an almost two-hour drive. It’s your word against mine, and it’s my car. Anyway, the luggage rack you borrowed without pay, so even if we included Sunday, I can demand it back now.”

“No point in arguing,” said Kalman. “Let’s ask Rabbi Dayan; whatever he rules.”

Dov called Rabbi Dayan. “I rented Kalman my mini-van and lent him my roof luggage rack. There’s a dispute between us whether we included Sunday in the agreement. Who is believed?”

“Kalman is entitled to hold the rented and borrowed items until the time he claims,” ruled Rabbi Dayan.

“Why is that?” asked Dov.

“The Gemara (B.M. 102b) discusses the case of a rental whose time frame is questionable,” replied Rabbi Dayan. “The ruling should be hamotzi meichaveiro alav hara’ayah (the burden of the proof is on the plaintiff). Regarding real estate, the landlord is considered muchzak (in possession of his property) and has the upper hand. However, regarding movable property such as a car and luggage carrier, the renter — who is holding the item — is considered muchzak (in possession).”

“What’s the difference?” asked Kalman.

“Tosafos (B.M. 103a s.v. pardisei) explain that although the rental item is supposed to return to its owner, the renter physically holds it and can hide it from its owner,” replied Rabbi Dayan. “Therefore, it differs from real estate that cannot be grabbed and hidden away from the landlord. Since Kalman is currently in possession and Dov is trying to claim it back from him, the burden of proof is on Dov to prove that Sunday was not included.” (See Shach 312: 14; SM”A 341:21; Nesivos 341:14; however, see Pischei Choshen, Sechirus 1:[14] citing Erech Shai.)

“I can understand the car rental, since he paid for it,” said Dov. “But why can’t I get back the luggage carrier, which was just borrowed?”

“It is important to emphasize that a loan for a set time is a legally binding commitment,” explained Rabbi Dayan. “Even though Kalman borrowed the luggage carrier without payment, he acquires the legal right to use it for the stipulated time. If there was no stipulated time frame, then you could demand it back any time” (C.M. 341:1).

“So Kalman is believed just on his word alone?” asked Dov.

“In truth, since you contradict him definitively,” answered Rabbi Dayan, “he is required to swear a shevuas heses (rabbinic oath). However, nowadays we avoid imposing oaths. In some cases, the beis din might seek a small compromise in lieu of the heses oath” (C.M.