13:15 When Pharaoh stubbornly refused55 to release us, the Lord killed all the firstborn in the land of Egypt, from the firstborn of people to the firstborn of animals.56 That is why I am sacrificing57 to the Lord the first male offspring of every womb, but all my firstborn sons I redeem.’
tnHeb “dealt hardly in letting us go” or “made it hard to let us go” (see S. R. Driver, Exodus, 110). The verb is the simple Hiphil perfect הִקְשָׁה (hiqshah, “he made hard”); the infinitive construct לְשַׁלְּחֵנוּ (léshallékhenu, “to release us”) could be taken epexegetically, meaning “he made releasing us hard.” But the infinitive more likely gives the purpose or the result after the verb “hardened himself.” The verb is figurative for “be stubborn” or “stubbornly refuse.”