Dreams about classrooms often symbolize learning, authority, and personal growth. In your dream, the act of biting off your fingers can represent feelings of self-sacrifice or a loss of control, particularly in a situation where authority figures are present. This might suggest you are grappling with demands from others or feeling pressured to conform to expectations.

The fact that you grew your fingers back indicates resilience and the ability to recover from difficult situations. It reflects your inner strength and capacity for renewal, showing that while you might face challenges, you ultimately have the resources to overcome them.

The teacher's arrest and the explanation of wanting to test people's willingness to comply could point toward feelings of distrust in authority or a critique of how people can be manipulated by those in power. It may suggest that you are reflecting on your own experiences with authority and how they impact your decisions.

Overall, this dream might be encouraging you to assess the influences in your life and to consider how you assert your own needs and boundaries. It could also be a reminder to trust your instincts and be cautious about blindly following others.