When the Yidden follow what Hashem tells them to do, Hashem gives them brachos.
But when the Yidden are not following Hashem, Hashem lets the goyim around them get strong and rule over them.
That's what happened to the Yidden many times during the years of the Shoftim.
After one of the Shoftim, Osniel ben Knaz, passed away, the Yidden again started not following the mitzvos properly. Because of this, Hashem let the king of Moav, Eglon, rule over them.
After the Yidden suffered under Eglon for 18 years, they cried out to Hashem in teshuvah, and asked Him to save them.
Hashem sent a new shofeit, Ehud ben Gera, to save the Yidden.
Ehud ben Gera was left-handed. He decided to use this to trick Eglon! He sharpened his sword on both sides, so it was sharp however you use it. He went to bring a present to the Eglon from the Yidden.
When he came to the palace, the guards searched him to see if he had a weapon. But they only searched him on one side, the left side, where most people carry their swords. They didn't realize that Ehud was left-handed, so he kept his sword on his right side!
Ehud ben Gera came in to the throne room of Eglon, who was a very fat king.
After giving the present to Eglon, he sent away everyone else. He said that he had a private message for the king!
"I have a message for you from Hashem," Ehud ben Gera announced.
Eglon stood up in kavod. Ehud pulled out his sword and stuck it deep into Eglon's stomach, killing him.
That was his message from Hashem — that the time of making the Yidden suffer was over.
Ehud left the palace, without telling anyone what he had done.
Eglon's soldiers didn't want to come in, because they thought that Eglon was using the bathroom and needed privacy. But after many hours, they opened the door. They found the king lying on the floor dead!
In the meantime, Ehud had run away. He told the Yidden to gather together. They were able to fight against Moav, and the Yidden were able to live in peace for 80 years after that.