He is wise in heart, and mighty in strength: who hath hardened himself against him, and hath prospered?
He is wise in heart and mighty in strength. Hebrew, 'Wise in heart (understanding)! And mighty in power!' God confounds the ablest arguer by His wisdom, and the mightiest by His power.
Hardened - namely, himself, or his neck (Proverbs 29:1) - i:e., defied God. To 'prosper,' one must fall in with God's arrangements of Providence and grace.