But Pharaoh hardened his heart this time as well, and he would not let the people go.

Exodus 4:21
The LORD instructed Moses, "When you go back to Egypt, see that you perform before Pharaoh all the wonders that I have put within your power. But I will harden his heart so that he will not let the people go.

Exodus 8:8
Pharaoh summoned Moses and Aaron and said, "Pray to the LORD to take the frogs away from me and my people. Then I will let your people go, that they may sacrifice to the LORD."

Exodus 8:15
When Pharaoh saw that there was relief, however, he hardened his heart and would not listen to Moses and Aaron, just as the LORD had said.

Exodus 8:31
and the LORD did as Moses requested. He removed the swarms of flies from Pharaoh and his officials and his people; not one fly remained.

Exodus 9:7
Pharaoh sent officials and found that none of the livestock of the Israelites had died. But Pharaoh's heart was hardened, and he would not let the people go.

1 Samuel 6:6
Why harden your hearts as the Egyptians and Pharaoh hardened theirs? When He afflicted them, did they not send the people on their way as they departed?

And Pharaoh hardened his heart at this time also, neither would he let the people go.