Paul expanded and applied it to the Jews and Greeks. Paul says they are under sin....and so is every other human.
Paul is writing to the Christians in Rome. Yes, he makes a case that all are under sin. But he is also making a case for those who will harden their hearts, and what they are capable of.
Pharaoh had a hard heart, and in fear of the Jews, he had the male children murdered.
NIV Exodus 1:15 The king of Egypt said to the Hebrew midwives, whose names were Shiphrah and Puah, 16 “When you are helping the Hebrew women during childbirth on the delivery stool, if you see that the baby is a boy, kill him; but if it is a girl, let her live.”
They cried out to the LORD, and the LORD heard their cries.
NIV Exodus 5:Pharaoh said, “Who is the Lord, that I should obey him and let Israel go? I do not know the Lord and I will not let Israel go.”
He had a choice to do what was right, but he did not act in accordance with what was right, and his sin against Israel increased by his behavior toward them.
Pharaoh hardens his heart again.
NIV Exodus 7:13 Yet Pharaoh’s heart became hard and he would not listen to them, just as the Lord had said.
And again...
22 But the Egyptian magicians did the same things by their secret arts, and Pharaoh’s heart became hard; he would not listen to Moses and Aaron, just as the Lord had said.
Jesus says many time, " for those who have ears". In other words, for those who are willing to hear. When we harden our heart, we stop listening to others.
Chapter 8 is interesting where he begs the frogs come to an end, but once they are, he hardens his heart again.
Exodus 8:15 But when Pharaoh saw that there was relief, he hardened his heart and would not listen to Moses and Aaron, just as the Lord had said.
Even the Pharaoh's advisors started to fear God, and recognized Him. But not Pharaoh.
18 Since the gnats were on people and animals everywhere, 19 the magicians said to Pharaoh, “This is the finger of God.” But Pharaoh’s heart was hard and he would not listen, just as the Lord had said.
Pharaoh would not listen.
, But in verse 28, he almost did...but changed his mind. Again, he had an opportunity to repent. But he grieved the Holy Spirit which convicted him of his sin.
Then Moses left Pharaoh and prayed to the Lord, 31 and the Lord did what Moses asked. The flies left Pharaoh and his officials and his people; not a fly remained. 32 But this time also Pharaoh hardened his heart and would not let the people go.
Exodus 9:8 . Yet his heart was unyielding and he would not let the people go.
When one refuses to soften their heart, and are causing great suffering on others, God will invoke justice, and harden their heart. Their destruction is emminent. There are no more offers of salvation
12 But the Lord hardened Pharaoh’s heart and he would not listen to Moses and Aaron, just as the Lord had said to Moses.