There are many examples of foreshadowing in the short story, "The Monkey's Paw." Let me offer two of these.
First, in the beginning of the story, Mr. White and his son, Herbert, are playing chess. Chess is a game of calculations and risks. Mr. White makes a poor move. Does he miscalculate, or take an excessive risk? We do not know for certain, but soon thereafter Herbert wins the game. This loss foreshadows that Mr. White will lose on a bigger scale. Mr. White will take a chance on the monkey's paw and make a wish that will bring suffering to his family.
Second, after Mr. White makes a wish for 200 pounds, Herbert is skeptical. He says:
"Well, I don’t see the money," said Herbert, picking it up. "And I am sure I never will."
This is foreshadowing of what will happen to Herbert. He will not see the money, because he will be dead. In fact, it is his death that will ensure that the Whites will have the 200 pounds.