"A Good Man is Hard to Find" by Flannery O'Connor has several examples of foreshadowing in it. Foreshadowing is when an author uses hints to suggest certain plot developments that will occur later on in the story.
The first example of foreshadowing in this short story, is when the grandmother is reading about the Misfit in in the newspaper at the beginning of the story. She then says that she "wouldn't take my children in any direction with a criminal like that a loose in it. I couldn't answer to my conscience if I did." Ironically, it is per her directions that lead them off the main road and right into the hands of the Misfit and his cronies. The discussion of the Misfit picks up later between Red Sam and the grandmother who discuss the his prison escape.
The second example of foreshadowing is a bit less obvious. Throughout the entire story, there is death imagery. At the beginning, as the Grandmother gets ready to go on the trip, she dresses in a way that is foreshadowing of her own death. She says she dresses so that "anyone seeing her dead on the highway would know at once that she was a lady." While on the highway, they pass five or six graves fenced in on the side of the road indicative of the deaths of the six passengers in the car. Finally, as they see the Misfit's car, it is described as a hearse - a vehicle in which the dead are carried. These images all foreshadow the death of the grandmother and her family.