Shlomo Goodman ran an organization, Mattan B’seiser, that distributed food packages to needy families. To help fund the organization, Mr. Goodman placed pushkes (tzedakah boxes) in many of the local shuls. Once a week, Shlomo would go around and collect the contents of the pushkes in a container.

He came to the Kehillah Shul. The shul treasurer, Mr. Marx, welcomed him. “Good morning, Shlomo!” he said. “It’s good to see you.”

“Likewise,” replied Shlomo.

“We just put your pushke away in the office,” said Mr. Marx. “I’ll get it for you.”

Mr. Marx came back a minute later. “Here it is,” he said. “I’ll empty the money into your container.”

Mr. Marx put the bills in the container and began transferring the coins. “Are you sure that you have the right pushke?” Mr. Goodman asked. “It looks a little different.”

Mr. Marx checked the label on the pushke. “You’re right!” he exclaimed. “I confused it with another pushke that looks similar.”

Mr. Marx went back to the office to get the correct pushke. 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. “How much was in your container?”

“I emptied the pushkes 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 few singles, and a lot of quarters. I’d estimate it was $20-$30.”

“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.

“Harav Yechezkel Landau, author of the Noda BiYehudah, was asked a similar question about 250 years ago,” replied Rabbi Dayan. “He writes that you are required to return only what you are certain was mixed in” (Noda BiYehudah, Y.D. 2:155; Pischei Teshuvah, Y.D. 259:13).

“Why is that?” asked Mr. Goodman.

“The Noda BiYehudah compares the amount in question to someone who does not know whether he borrowed, who is not legally liable,” replied Rabbi Dayan. “Here, too, aside from the amount that is certain, you don’t know whether anything more was put in” (C.M. 75:9).

“Doesn’t the borrower have a moral obligation (chiyuv b’dinei Shamayim) in such a case, 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,” added Rabbi Dayan, “the Noda BiYehudah writes that even if Mr. Marx had a definite claim, you would have no obligation whatsoever beyond what you are certain about, because you never accepted liability for the other money, neither as a borrower nor as a guardian. Similarly, even according to the stringent opinion that when neither the lender nor the borrower remember how much was borrowed, the borrower has a moral obligation to seek an acceptable compromise (C.M. 75:18), you have no obligation to return beyond what you are certain, since you never accepted any responsibility for the money mistakenly put in, nor are you expected to know how much it was.” (See, however, Y.D. 259:5 and Erech Shai there.)

“What about Mr. Marx?” asked Mr. Goodman.

“Since the shul agreed to look after the other pushka, he was responsible as a guardian and was careless,” replied Rabbi Dayan. “He has a moral obligation to fill in the questionable amount.”