Tuvaṭakasuttaniddesa

Suttapiṭaka · Khuddakanikāya · Mahāniddesa · Vol. 29 · Section 778

[778] And having understood this Dhamma, a bhikkhu, investigating, ever mindful, should train; having known quenching (nibbuti) as 'peace,' he should not be heedless in the teaching (sāsana) of Gotama.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.