'Harder' in the Bible

LORD, don't your eyes look for truth? You struck them, but they didn't flinch. You brought them to an end, but they refused to receive discipline. They made their faces harder than stone, and they refused to repent.

I'm making you harder than flint like diamond! So you are not to fear them or be intimidated by how they look at you, since they're a rebellious group."

So the Jewish leaders were trying all the harder to kill him, because he was not only breaking the Sabbath but was also calling God his own Father, thereby making himself equal to God.

But by God's grace I am what I am, and his grace shown to me was not wasted. Instead, I worked harder than all the others not I, of course, but God's grace that was with me.