Joseph states he is the greatest person in the house and Potiphar has put everything (including her) into Joseph’s hand. We are supposed to notice that Joseph has placed himself above her as well as above all the other slaves. They are his new household unit, but the same arrogance he had with his brothers he has here. Of course, Potiphar is going to know what happened. Slaves see what’s going on, and someone will pass the word
