Parallel
Exodus 10:20
Swete's Septuagint · Berean Standard Bible
καὶ ἐσκλήρυνεν Κύριος τὴν καρδίαν Φαραώ, καὶ οὐκ ἐξαπέστειλεν τοὺς υἱοὺς Ἰσραήλ.
But the LORD hardened (note: Or stiffened or strengthened; also in verse 27) Pharaoh’s heart, and he would not let the Israelites go.