A Polish Jew once came to the Yismach Yisroel of Alexander zy”a and related that although he owned a store, he had very few customers and he was unable to make a sufficient livelihood. From the course of the conversation, the Rebbe was able to discern that the man’s store was open on Shabbos.
The Yismach Moshe told him, “I can guarantee you success in your business on one condition. You must take me as a 15% partner without me having to invest one dollar into the business. If you accept these terms, I promise you success.”
Of course, the man agreed to the deal, and a contract was written up.
The Yismach Moshe then told him, “Since I now own one-seventh of your store and I am entitled to one-seventh of the profits, I choose to take Shabbos as my day. All the profits you earn on Shabbos will be mine, while the profits from the other six days will be yours Therefore, I ask you to close the store on Shabbos.”
The man understood what the Rebbe was saying. From then on, he closed his store on Shabbos and he saw much financial success.
Reprinted from the Parshas Vayakhel-Pekudei 5786 email of The Way of Emunah: Collected Thoughts on the Weekly Parshah from Rabbi Meir Isamar Rosenbaum.