Romans 9:18

So then he has mercy on whom he will, and whom he will, he hardens.

And in them is being fulfilled that prophecy of Isaiah which says. "Hearing you will hear and not understand; Seeing you will see and not perceive;

"Go to the people and tell them, You will hear and hear, and by no means understand; And will look, and by no means see.

So God gave them up in the lusts of their hearts to impurity, to the dishonoring of their own bodies;

Now law was brought in so that transgression might abound; but where sin abounded, grace super-abounded;

His words to Moses are. I will have mercy on whom I choose to have mercy; I will have compassion on whom I choose to have compassion.

What then? that which Israel has been seeking for, that he has not obtained; but the chosen have obtained it, and the rest have been hardened.

and to the praise of his glorious grace which he graciously bestowed upon us in the Beloved.

and with all deceit of unrighteousness for those who are perishing, because they did not receive the love of the truth for their salvation.

Treasury of Scripture Knowledge

Therefore hath he mercy on whom he will have mercy, and whom he will he hardeneth.