Romans 9:16

9:16 So then, it does not depend on human desire or exertion, but on God who shows mercy.

Romans 9:18

9:18 So then, God has mercy on whom he chooses to have mercy, and he hardens whom he chooses to harden.

Romans 11:30-32

11:30 Just as you were formerly disobedient to God, but have now received mercy due to their disobedience, 11:31 so they too have now been disobedient in order that, by the mercy shown to you, they too may now receive mercy. 11:32 For God has consigned all people to disobedience so that he may show mercy to them all.