''He shall return the article that he stole, the withheld funds, the article left for safekeeping, the found article.... or anything else regarding which he swore falsely" [Vayikra 5:23-24]
Gedolei Yisrael have always exercised great caution when dealing with the money of others, so that they would not be guilty of the severe transgression of theft.
by Rabbi Yisrael Bronstein
One erev Shabbos, when R' Isser Zalman Meltzer returned from the mikveh, he suddenly realized that he had used two clothing cubbies at the mikveh.
Perhaps I took someone else's space, thought R' Meltzer. I might very well owe the mikveh attendant twice the amount that I usually pay!
One of his family members saw how much the matter was troubling R'Meltzer, so he offered to go to the mikveh and pay the attendant for the extra cubby.
"It is I who must go" replied R' Meltzer. "For the halachah states explicitly that one who steals from his fellow must not only repay him, but he must verbally appease him as well. The responsibility to appease the attendant is my responsibility alone."