Deuteronomy 2:30

And Yahweh said to Moses, “When you go to return to Egypt, see to it that all the miraculous wonders which I have put in your hand, that you do them before Pharaoh; but as for Me, I will harden his heart with strength so that he will not let the people go.

Then Israel sent messengers to Sihon, king of the Amorites, saying,

after he had struck down Sihon the king of the Amorites, who lived in Heshbon, and Og the king of Bashan, who lived in Ashtaroth and Edrei.

“Then you came to this place, and Sihon the king of Heshbon and Og the king of Bashan came out to meet us for battle, but we struck them down;

‘And Israel sent messengers to Sihon king of the Amorites, the king of Heshbon, and Israel said to him, “Please let us pass through your land to our place.”

So the king did not listen to the people; for it was a turn of events from Yahweh, that He might establish His word, which Yahweh spoke through Ahijah the Shilonite to Jeroboam the son of Nebat.

You will give them dullness of heart; Your curse will be on them.

So then He has mercy on whom He desires, and He hardens whom He desires.