Thou hast trusted in thy wickedness; i.e. in thy incantations and spells, which were supposed to work in secret, and which could not be counteracted if their victim was not aware of them. Thy wisdom and thy knowledge, it hath perverted thee.
The astronomical "wisdom and knowledge" of the Babylonians, confessed by the Greeks to have been the origin of their own astronomical knowledge, led them on to that perversion of true science, astrology, which, when once entered upon, seduces the mind from all genuine and fruitful study of the celestial phenomena, and leads it into a labyrinth of absurdities.
It also puffed them up, and made them regard themselves as altogether superior to other nations (see the comment on Isaiah 47:8, sub fin.).