ויאמר לכי שאלי לך כלים מן החוץ ... (מלכים ב' ד-ג)
The wife of Ovadia HaNavi was at a loss. Her husband had died leaving her to fend for her children who were being threatened by Yehoram, son of King Achav of Malchus Yisroel. Achav had lent Ovadia money with interest, and the righteous Navi used that money to financially support the prophets he was hiding from King Achav who was seeking their deaths. Ovadia’s wife cried out to Elisha HaNavi who instructed her to borrow vessels and bring them into her house after which he performed a miracle and her single jug of oil became a never-ending supply thereby making her quite wealthy. Why did she have to borrow other vessels? Surely the miracle could have occurred regardless.
R’ Yosef Rosen zt”l, the Rogatchover Gaon, answers that a Jew is forbidden to charge and benefit from Ribbis - interest. As such, even though King Achav was a wicked man, he was nevertheless Jewish, and she was therefore forbidden from benefiting from such a loan. Thus, explains the Rogatchover brilliantly, Elisha instructed her to borrow vessels from neighbors so that she would not actually accept the money that would be benefited from the oil - it would be considered hefker. Ovadia’s wife would then be able to take that money and pay back the loan without transgressing any halachos.
It is very important for every Jew to remember that even when we do good deeds and perform mitzvos, the manner in which we do them is important as well, and we must be cognizant of how we go about practicing as Torah Jews.