In the Hebrew it is, he doth not afflict from his heart, that is, with pleasure and delight; or (which seemeth the best sense to me) not from his own mere motion without a cause given him from the persons afflicted. Hence judgment is called God's strange work. Showing mercy is his proper natural work, which floweth from himself without any cause in the creature. Judgment is his strange work, to which he never proceedeth but when provoked, and as it were forced from the creature, whence it followeth that he cannot delight in it.
Related Commentaries of Lamentations 3:33
Lamentations 3:33
33 For he doth not afflict willinglyh nor grieve the children of men.