sn.36.9 Saṁyutta Nikāya (Linked Discourses)

Impermanent

“Mendicants, these three feelings are impermanent, conditioned, dependently originated, liable to end, vanish, fade away, and cease.
What three?
Pleasant, painful, and neutral feeling.
These are the three feelings that are impermanent, conditioned, dependently originated, liable to end, vanish, fade away, and cease.”