Shlomo Goodman ran an organization, Matan B’seiser, which distributed food packages to needy families in his neighborhood. To help fund the organization, Mr. Goodman placed pushkas (tzedakah boxes) in many of the local shuls.
Once a week, Shlomo would go around after Shacharis from shul to shul and collect the contents of the pushkas into a container.
One morning, he came to the Kehilla Shul. The gabbai of the shul, Mr. Marx, welcomed him. “Good morning, Shlomo!” said the gabbai. “It’s always good to see you.”
“Likewise,” replied Shlomo.
“You’re here for your pushka, I assume,” said Mr. Marx. “We just put it away in the office; I’ll get it for you.”
Mr. Marx came back a minute later. “Here it is,” he said. “I’ll pour it into your container.”
Mr. Goodman opened his container. Mr. Marx put the bills in the container and began shaking out the coins. “Are you sure that you have the right pushka?” Mr. Goodman asked. “It’s looks a little different.”
Mr. Marx stopped shaking, and checked the label on the pushka. “You know, you’re right!” he exclaimed. “I got confused with another pushka that looks similar.”
Mr. Marx went back to the office to get the correct pushka. When he returned, Mr. Goodman was lost in thought. “Do you know how much money you put in?” he asked Mr. Marx.
“No,” replied Mr. Marx. “Do you know how much was in your container?”
“I emptied the pushkas from a few other shuls,” answered Mr. Goodman. “I have no idea how much money there was.”
“I can’t say for sure how much I put in,” said Mr. Marx. “There was a ten dollar bill, a bunch of singles, and a lot of quarters. I’d estimate it was twenty-five to forty dollars.”
“I don’t want to take money from the other organization,” said Mr. Goodman. “Let me give Rabbi Dayan a call.”
He called Rabbi Dayan and explained the situation. “How much should I take out of the container?” he asked.
“R. Yechezkel Landau, author of the Noda B’Yehuda, was asked a similar question about 250 years ago,” replied Rabbi Dayan. “He writes that you are liable to return only what you know is not yours, the amount you are certain was mixed in.” (Noda B’Yehuda Y.D. 2:155; Pischei Teshuvah Y.D. 259:13)
“Why is this?” asked Mr. Goodman.
“The Noda B’Yehuda compares the amount in question to a case of someone who does not know whether he borrowed, who is not legally liable,” replied Rabbi Dayan. “Similarly, aside from the amount that is certain, you don’t know whether anything more was put in the container.” (C.M. 75:9)
“Doesn’t the borrower have a moral obligation – chiyuv b’dinei shamayim – though?” asked Mr. Goodman. “Similarly, wouldn’t I have a moral obligation for the questionable extra?”
“The borrower has a chiyuv b’dinei shamayim only if the plaintiff makes a definitive claim that he lent,” replied Rabbi Dayan. “Where the lender is also not sure, the borrower does not have even an obligation b’dinei shamayim. Here, Mr. Marx does not have a definite claim how much he put in.” (C.M. 75:10)
“Furthermore,” concluded Rabbi Dayan, the Noda B’Yehuda writes that in our case you would have no obligation whatsoever beyond what you are certain about, even if Mr. Marx had a definite claim. This is because you never accepted any liability for the money, neither as a borrower nor as a guardian. Therefore – even according to those who maintain that when neither the lender nor the borrower remembers how much was borrowed the borrower has a moral obligation to achieve an acceptable compromise – here there is no need for you to return beyond what you are certain, since you never accepted any form of responsibility for the money mistakenly put in, nor are you expected to know how much it was.” (See C.M. 75:18; Shach 75:67)