וַיֹּ֤אמֶר יְהוָה֙ אֶל־מֹשֶׁ֔ה לֹא־יִשְׁמַ֥ע אֲלֵיכֶ֖ם פַּרְעֹ֑ה לְמַ֛עַן רְב֥וֹת מוֹפְתַ֖י בְּאֶ֥רֶץ מִצְרָֽיִם׃
L’Éternel avait dit à Moïse: "Pharaon ne vous cédera point, afin que mes miracles se multiplient dans le pays d’Égypte."
Akeidat Yitzchak
The observation about G-d having hardened the spirit of Sichon King of the Emorites, which was referred to earlier, is to be understood in a similar vein. Sichon, who had observed that Israel seemed to have avoided battling the Moabites or the Edomites and had detoured around their respective countries, concluded that Israel's motive had been fear. Thus he felt encouraged to assume a militant posture. This resulted in his defeat and the conquest of his lands by the Israelites. But there had been no interference with his freedom of choice.