20 But the LORD hardened Pharaoh's heart, so that he would not let the children of Israel go.
Exodus 10:20 Cross References - KJV
Exodus 4:21
21 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 7:13-14
Exodus 9:12
12 And the LORD hardened the heart of Pharaoh, and he hearkened not unto them; as the LORD had spoken unto Moses.
Exodus 11:10
10 And Moses and Aaron did all these wonders before Pharaoh: and the LORD hardened Pharaoh's heart, so that he would not let the children of Israel go out of his land.
Deuteronomy 2:30
30 But Sihon king of Heshbon would not let us pass by him: for the LORD thy God hardened his spirit, and made his heart obstinate, that he might deliver him into thy hand, as appeareth this day.
Isaiah 6:9-10
9 And he said, Go, and tell this people, Hear ye indeed, but understand not; and see ye indeed, but perceive not.
10 Make the heart of this people fat, and make their ears heavy, and shut their eyes; lest they see with their eyes, and hear with their ears, and understand with their heart, and convert, and be healed.
John 12:39-40
Romans 9:18
18 Therefore hath he mercy on whom he will have mercy, and whom he will he hardeneth.