Notes on Book of Exodus (Author Bishop Richard Challoner (ed.))
8:15Hardened his own heart: By this we see that Pharao was himself the efficient cause of his heart being hardened, and not God.--See the same repeated in ver. 32. Pharao hardened his heart at this time also: likewise chap. 9.7, 35, and chap. 13.15.
Original Douay-Rheims from Project Gutenberg - Massive cleanup of OCR problems and editing done locally.