I don't know about you, but I'm starting to see that "thus says the Lord" statements in Exodus are primarily concerned with showing God as the Redeemer who wants us to see our desperate need of his redemption. The formula "coh amar y'adonai" - thus says the Lord - has been used by God for two purposes so far: to let Pharaoh know God wants Egypt to be released from an abusive connection to Israel, and to let Israel know God wants them to be able to serve and worship him.
In Exodus 10:3, God heightens this desire by making Pharaoh's need and God's provision more explicit: "So Moses and Aaron came in to Pharaoh and said to him, 'Thus says the LORD God of the Hebrews: "How long will you refuse to humble yourself before Me? Let My people go, that they may serve Me"'" (NKJV). What's interesting about this passage is the reference to humility. With respect to Pharaoh, God tells Moses and Aaron in Exodus 10:1 that he has "hardened his heart and the hearts of his servants," but then God asks Pharaoh in Exodus 10:3, "How long will you refuse to humble yourself before Me?" But God is not playing a game with Pharaoh. Verses 1 and 3 make clear that God is trying to free Pharaoh from himself.
The word for "hardened" in verse 1 is linguistically related to the Hebrew word for "glory." In many ways, God is showing Egypt and Israel his glory by attempting to cause that divine glory to shine on Pharaoh. It is Pharaoh's heart, not God, that responds to the glory of God by becoming "heavy" or "hard" through self-exaltation. What Pharaoh needs is humility, because humility with God results in a person being exalted and glorified by God. In reality, God's "thus says the Lord" is intended to free Pharaoh from the tyranny of his own heart and empower Israel for service to God.
Friends, God wants you to be whole, healed, and restored, and he invites you to trust him to do this work to your glory and exaltation - because "thus says the Lord." God bless.