How do we know that God is sovereign in sending plagues?

God's sovereignty is displayed significantly through the plagues of Egypt, particularly in Exodus 8:20-32, where He directly communicates the punishment that will come if Pharaoh does not heed His command. Unlike previous plagues that utilized Aaron's rod, this plague of flies was announced by God's own voice. This indicates that the power of God is distinct from the instruments or messengers He uses, highlighting that true authority comes from His sovereign will. God's proclamation of the plagues shows His unmatched authority over nature and human rulers, compelling acknowledgment of His supremacy and leading us to understand His governance over all creation.