Though I have taught and strengthened their arms, Yet they plot evil against me.
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.