Hardening of Pharaoh's Heart

A light, casual reading of Scripture can sometimes lead us to erroneous conclusions. A deeper examination of the text often clears things up. Consider the following verse:
And the LORD said unto Moses, When thou goest to return into Egypt, see that thou do all those wonders before Pharaoh, which I have put in thine hand: but I will harden his heart, that he shall not let the people go. (Exodus 4:21)

Keyed to the phrase "I will harden his heart" is the following note from page 68 of The Dake Annotated Reference Bible:

Heb. chazaq, to brace or tighten as opposed to relax (v. 21; 7:13, 22; 8:19; 9:12, 35; 10:20, 27; 11:10; 14:4, 8, 17; Josh. 11:20).

God is often said to do the things He permits. God gave Pharaoh the occasion to resist Him and harden his own heart (v. 21; 9:12; 10:1, 20, 27; 11:10; 14:8; cp. Rom. 9:18) in the same way that the gospel saves or damns today; softens or hardens; and makes alive or kills all who hear it (Rom. 2:4-11; 2 Cor. 2:15-16). Any judgment or calamity which does not break the nature and subdue the life only hardens it. As the sun hardens clay and softens wax, so it is with truth. The result is not in the sun (or God) but in the materials.

Potiphar and his wife
Israel "borrowing" from Egypt
The Testimony
The Glory of God in Moses' face
The Glory of the Lord
Living a Long Life
Sickness and Disease