וַיֶּחֱזַק֙ לֵ֣ב פַּרְעֹ֔ה וְלֹ֥א שָׁמַ֖ע אֲלֵהֶ֑ם כַּאֲשֶׁ֖ר דִּבֶּ֥ר יְהוָֽה׃ (פ)
And Pharaoh’s heart was hardened, and he hearkened not unto them; as the LORD had spoken.
Read halakhic rulings (Jewish law) on Exodus 7:13: and classical halakhic sources.