Today's Gospel is one of the stranger stories Luke offers us. Jesus had cast out a demon, and the people around him muttered that the devil made him do it: that it was by Satan's power that the demon had come out. As if God taking action to rescue us from evil and harm was simply too good to be true. And then some other bystanders had the gall to ask him for "a sign from heaven"! (I suppose an exorcism didn't qualify as a "sign from heaven".)
It was enough to make even God roll his eyes.