Romans 9:18

Therefore. Again, as in verse 16, Paul states the general inference to be drawn from the examples cited.

Hath he mercy. See on verse 15.

Will. Greek thelo, “to wish,” or “to desire.”

He hardeneth. Greek skleruno. The only other NT occurrences of this word are in Acts 19:9; Heb. 3:8, 13, 15; 4:7. In Exodus the hardening of Pharaoh’s heart is sometimes described as self-produced (Ex. 8:15, 32; etc.) and sometimes as produced by God (Ex. 4:21; 7:3; etc.). In the Bible God is often represented as doing that which He does not prevent (see on 2 Chron. 18:18). Paul here chooses the latter representation as better suited to his purpose in this context. The hardening of a man’s heart is the result of rebellion against the divine revelation and rejection of the Divine Spirit. Paul has spoken earlier in this epistle of how God turns a man over to the inevitable consequences of his stubborn disobedience (Rom. 1:24, 26, 28). For a discussion of the hardening of Pharaoh’s heart see on Ex. 4:21.