So the heart of Pharaoh was hardened uses the verb meaning “to be strong.” (See the discussion at 4.21.) Note that this is one of six theologically neutral references in Exodus to the Pharaoh’s heart, for apart from verse 34 there is no indication as to who caused it to be hard. (This is discussed further at 7.13.) As in New International Version, therefore, it is more accurate to translate “hard” than hardened. The meaning, of course, is that he “remained as stubborn as ever.” Good News Translation, Contemporary English Version, and others omit So the heart of Pharaoh was hardened as being repetitious.

And he did not let the people of Israel go repeats the same formula used in 8.32; 9.7; and 11.10. He did not let … go is literally “he did not send.” New Revised Standard Version has changed the did not in these verses to “would not,” as in Good News Translation and others. As the LORD had spoken through Moses is literally “as Yahweh spoke by the hand of Moses.” King James Version and American Standard Version translate “by Moses.” This is not quite the same meaning as in 9.12, where it says “to Moses.” The implication here is that Moses (or Aaron) had earlier explained this to the Israelites. (See 3.19 and 4.28-30.)

Quoted with permission from Osborn, Noel D. and Hatton, Howard A. A Handbook on Exodus. (UBS Helps for Translators). New York: UBS, 1999. For this and other handbooks for translators see here .