Welcome to the Daily Holy Story.
About 450 years ago, in the time of Maran (our master) Bet Yosef, known as Rabbi Yosef Karo, there lived in Krakow, Poland, a very great rabbi named Rabbi Moshe Isserles, better known as the Rama. The Rama was very friendly with the Bet Yosef, and because of their friendship, Rabbi Yosef Karo gave the Rama a Sefer Torah (Torah scroll) as a gift. To this day, the Ashkenazim (Ashkenazi Jews) use that Sefer Torah to write their Sefer Torah, and it is called Ketav Bet Yosef, the writing of the Bet Yosef.
In the time that the Rama lived in Krakow, Poland, many Goyim (non-Jews) celebrated their holiday once a year. Before the holiday, they would kidnap a Jewish boy and, on the holiday, throw him into the river and drown him. This custom of the Goyim continued for many years. As that day drew closer on the calendar, the Jewish people in Krakow would all hide in their homes out of trepidation and fear that one of their children would be kidnapped and drowned in the river near Krakow. Finally, the Jews couldn't take it anymore. A group of Jews went to visit the Rama and told him, with tears in their eyes, “Rabbi, Rabbi, what are we going to do? The Goyim keep kidnapping our children near their holiday and drowning a baby Jewish boy in the river.”
When the Rama heard that, he fasted for three days and then wrote holy names of Hashem on a parchment. He went to the river and said, “River, river”—speaking to the minister of the river, the angel of the river—and said to the river, “I command you: the next time the non-Jews bring a Jewish child to you and throw him into you, spit that Jewish boy out, and swallow the Goy that threw him into the river, and make sure the Goy gets drowned. And if you don't do what I'm saying, if you don't listen to what I'm saying, then I will make sure that you dry up.”
Sure enough, that year the Goyim took a Jewish boy, threw him into the river, and, before their eyes, the river spit out the Jewish boy, swallowed the Goy who threw him into the river, and drowned the Goy. The Goyim were amazed and bewildered. The following year, they did the same thing, and again the river spit out the Jewish boy and swallowed the Goy that tried to drown him, and he drowned. This went on for three, four years, until the Goyim gave up and stopped drowning Jewish children in the river of Krakow.
After 10 years, the Goyim forgot about it. They took a Jewish boy and threw him into the river. Sure enough, the river in Krakow drowned the Jewish boy. When the Jewish people came to the Rama and told him what had happened, he told them, “Don't worry; there will no longer be a river near Krakow.” Sure enough, the river dried up, to the dismay of the Goyim, and they could no longer drown any Jewish children.
Have a wonderful, wonderful day.