ANSWER: The Am. Revision is, ''For this cause have I made thee to stand," after, as the context shows, he had been "smitten with pestilence." There is no reference here to his birth. There are three forms in which the hardening of his heart is expressed. In verses 34, 35, Pharaoh "Hardened his heart" and "the heart of Pharaoh was hardened." This explains verse 12, "and the Lord hardened Pharaoh's heart" as the result of his resistance to the Divine chastisements. In no other sense did God harden his heart than to let him rush forward in such a course of rebellion as issued in his hardening his own heart.
— From Steele's Answers pp. 35, 36.