“Bhikkhus, these four things are actual, unerring, not otherwise. What four?
“‘This is suffering’: this, bhikkhus, is actual, unerring, not otherwise. ‘This is the origin of suffering’: this is actual, unerring, not otherwise. ‘This is the cessation of suffering’: this is actual, unerring, not otherwise. sn.v.431 ‘This is the way leading to the cessation of suffering’: this is actual, unerring, not otherwise.
“These four things, bhikkhus, are actual, unerring, not otherwise.
“Therefore, bhikkhu, an exertion should be made to understand: ‘This is suffering.’… An exertion should be made to understand: ‘This is the way leading to the cessation of suffering.’”