Jesus had just cast out a demon from a man, but was accused by the people of performing the act by the power of the devil. The people tested Jesus by asking Him for a sign from heaven (Luke 11: 14-17). Knowing their evil intentions, Jesus addresses the people by saying that no sign would be given except the sign of Jonah. He then concludes by warning the people to be careful lest the light in them was darkness (Luke 11: 29 – 36).