Romans 9:18

This verse is a short repetition of the foregoing argument. Therefore hath he mercy on whom he will have mercy: see Romans 9:15, and the notes there. And whom he will he hardeneth; i.e. in a judicial way. Besides natural hardness, which is in all men, and is hereditary to them; and habitual hardness, which is contracted by a custom in sin, as a path is hardened by the continual trampling of passengers; there is judicial or judiciary hardness, which is inflicted by God as a punishment. Men harden their own hearts sinfully, (so it is thrice said of Pharaoh in Exodus, that he hardened his own heart, Exodus 8:15,32 Exodus 9:34), and then God hardens their hearts judicially: so it is often said of God in Exodus, that he hardened Pharaoh's heart, Exodus 7:13 Exodus 9:12, Exodus 10:1,20,27 14:8. God is not said properly to harden the hearts of men; i.e. he doth not make their soft hearts hard, nor doth he put hardness into the hearts of men, (as our adversaries slanderously report us to affirm), nor doth he barely permit or suffer them to be hardened (which is the opinion of the papists about this matter); but two ways may he be said to harden sinners:

1. By forsaking them, and not softening their hearts: as darkness follows upon the sun's withdrawing of his light, so doth hardness upon God's withholding his softening influence.

2. By punishing them; he inflicts further hardness, as a punishment of former hardness; and this he infuseth not, but it is effected either: a) By Satan, to whom hardened sinners are delivered up; or, b) By themselves, they being given over to their own hearts lusts; or, c) By God's word and works, which accidentally harden the hearts of men, as might be shown. \see Romans 9:19\ See Poole on "Romans 9:19".