Musar for Bava Kamma 110:15

We find in the Torah that if one stole from his friend, his amendment is to return the stolen object to its owner, and if he grieved or shamed him, to conciliate him and be forgiven by him. But one who habituates himself to this sin [lashon hara] certainly stirs up the Great Adversary to condemn the world. Who knows how many were impoverished because of him [the speaker] and how many died because of him? And though by the laws of man he cannot be punished for this, still, by the laws of Heaven, even though this is gramma [(an act of indirect causation)], he is not absolved of this. Therefore, one who heeds his soul should take great heed of this.