The astrologers finally crack. Targum Pseudo-Jonathan on Exodus 8:15 records their confession: This is not by the power or strength of Mosheh and Aharon; but this is a plague sent from before the Lord.
Every word of that sentence is a defeat for Egyptian religion. First, the magicians concede that Moses and Aharon are not the agents — they are merely messengers. Second, they name the source: the Lord, the God of the Hebrews whom Pharaoh had once dismissed as unknown. Third, they call the lice not sorcery but a plague — an act of sovereign judgment.
And yet. The design of Pharoh's heart was strengthened, and he would not hearken to them. Pharaoh's own advisors have converted, but Pharaoh himself has not. The advisors confess; the king refuses. The meturgeman uses the word taqif — strong, fortified — to describe a heart that has heard the truth and chosen to get harder.
This is the fork in the road that every listener faces. When wise people around you begin to admit that God is in charge, what do you do? The astrologers bent. Pharaoh did not. The plagues will continue because only one of the two listened.
The takeaway: a person can stand in a room full of repentance and still be the only one who refuses to repent. That stubbornness is also a choice, and it has a cost.