The Yoga Sutras of Patanjali
purvaka mrdu-madhyadhi-matra duhkhajnanananta-phala iti pratipaksa-bhavabam
Negative thoughts are violence, etc. The may be [personally] performed, performed on one’s behalf by another, or authorized by oneself; they may be triggered by greed, anger, or delusion; and they may be slight, moderate, or extreme in intensity. One should cultivate counteracting thoughts, namely, that the end results [of negative thouhgts] are ongoing suffering and ignorance.