What does the Bible say about God's sovereignty over Pharaoh's heart?

In the context of Exodus, God hardened Pharaoh's heart multiple times to demonstrate His power and bring about the deliverance of Israel. This act of hardening was not arbitrary but was part of God's sovereign plan to display His glory through the plagues. Romans 9:18 states, 'Therefore hath he mercy on whom he will have mercy, and whom he will, he hardeneth.' This emphasizes God's absolute sovereignty in the affairs of mankind, where He determines the fate of individuals according to His will, as a potter does with clay. God does not owe an explanation for His actions to humanity, as He is the Creator and we are but His creation.