They are all adulterers. They are burning like an oven that the baker stops stirring, From the kneading of the dough, until it is leavened.
The bakers would usually set the fire in the ovens at night and after building the fire in the oven at night, they would go to bed. They would knead the dough, set it aside and they'd go bed and they wouldn't rise until the dough had been leavened. And, of course, when they rose then the oven was all heated and ready for the bread. And so he uses that as a figure of speech actually, the heated oven to the heated passions of these people in their adulterous relationships.