For they verily for a few days chastened us after their own pleasure; but he for our profit, that we might be partakers of his holiness.
Wherein the chastisement of our heavenly Father is preferable to that of earthly fathers.
For a few days, х pros (G4314) oligas (G3641) heemeras (G2250)] - with a view to our well-being in the few days of earthly life.
After their own pleasure, х kata (G2596) to (G3588) dokoun (G1380) autois (G846)] - 'according to what seemed fit to themselves.' Their rule of chastening is their own often-erring judgment or caprice. The two defects of human education are: (1) An undue view to the interests of our short earthly term of days;
(2) The absence in parents of our heavenly Father's unerring wisdom.
'They err at one time in severity, at another in indulgence (1 Samuel 3:13; Ephesians 6:4), and do not so much chasten as THINK they chasten' (Bengel).
That we might be partakers of his holiness - holy as He is holy (John 15:2; 1 Peter 1:15-16). To become holy like God is to be educated for passing eternity with God (Hebrews 12:14; 2 Peter 1:4). So 'partaking of God's holiness' contrasts with the "few days" of this life for which earthly fathers generally educate their sons.