The correct answer to this open question is the following.
Justinian states that the laws of the state are subject to the "tacit consent of the people."
My explanation would be the following.
The government creates laws. And laws are created to protect people and having a peaceful society. According to Justinian, laws are not created to oppress people, but to allow harmonic relationships in society.
An example of recent times would be when the government enforces legislation to protect the interest of the citizens instead of supporting the particular interest of political groups or associations. The government is to serve the people, not personal agendas.