God chooses (Rom 9:18)

“Thus,

God has mercy

Upon whomever he wills.

He hardens

The heart

Of whomever he wills.”

ἄρα οὖν ὃν θέλει ἐλεεῖ, ὃν δὲ θέλει σκληρύνει.

Paul said that thus (ἄρα οὖν) God has mercy (ἐλεεῖ) upon whomever he wills (ὃν θέλει).  He hardens the heart (σκληρύνει) of whomever he wills (ὃν δὲ θέλει).  Paul indicated that God could do whatever he wanted to do.  He could give mercy or harden the hearts of everybody or anybody.  This was God’s choice, his will.  Some would get mercy, but others would get a hardened heart.  Would you like to have mercy?