2A disciple of the Buddha, mindful,
Concentrated, comprehending clearly,
Understands feelings
And the origin of feelings,

3Where they finally cease,
And the path leading to their destruction.
With the destruction of feelings
A bhikkhu is hungerless and fully quenched. [n.22] Since these verses (and those in the suttas to follow) are not expressly ascribed to the Buddha, I do not enclose them in quotation marks. Though several have parallels in other texts, where they are ascribed to the Buddha, here they seem to have been added by the redactors, perhaps quoting from these other sources.
The verse alludes to the Four Noble Truths, with feeling in the place of suffering (on the ground that "whatever is felt is included in suffering" and because feeling is one of the five aggregates mentioned in the formula for the first truth). Spk points out that two terms respectively signify serenity and insight (Spk-pṭ: samāhito and sampajāno); the rest, the Four Noble Truths. "Hungerless" (nicchāto) means without craving, and "fully quenched" (parinibbuto) implies the full quenching of defilements (kilesaparinibbāna). Thus the verses are all-inclusive, comprising all states of the four planes (see n. 6).

2Samāhito sampajāno,
sato buddhassa sāvako;
Vedanā ca pajānāti,
vedanānañca sambhavaṁ.

3Yattha cetā nirujjhanti,
maggañca khayagāminaṁ;
Vedanānaṁ khayā bhikkhu,
nicchāto parinibbuto"ti.