Guarding
Ārakkha Sutta  (AN 4:117)

“Monks, there are four instances where, for one’s own sake,1 heedfulness and a guarding through mindfulness & awareness should be practiced. Which four? [Thinking,] ‘Don’t let my mind become impassioned with regard to things that excite passion,’ heedfulness and a guarding through mindfulness & awareness should be practiced. [Thinking,] ‘Don’t let my mind become averse with regard to things that excite aversion,’ heedfulness and a guarding through mindfulness & awareness should be practiced. [Thinking,] ‘Don’t let my mind become deluded with regard to things that excite delusion,’ heedfulness and a guarding through mindfulness & awareness should be practiced. [Thinking,] ‘Don’t let my mind become intoxicated with regard to things that excite intoxication,’2 heedfulness and a guarding through mindfulness & awareness should be practiced.

“When, in a monk, from lack of passion, the mind is not impassioned with regard to things that excite passion; when, from lack of aversion, the mind is not averse with regard to things that excite aversion; when, from lack of delusion, the mind is not deluded with regard to things that excite delusion; when, from lack of intoxication, the mind is not intoxicated with regard to things that excite intoxication, then he isn’t stiff with fear, doesn’t tremble, doesn’t shake, doesn’t feel fright, nor is he influenced by the words of [other] contemplatives.”