Ajjhattikāyatanasutta

Suttapiṭaka · Saṁyuttanikāya · Mahāvaggasaṁyutta · Vol. 19 · Section 1689

[1689] Bhikkhus, these are the four noble truths (ariyasacca). Therefore, bhikkhus, exertion should be made [to realize]: "This is suffering (dukkha)" … "This is the way of practice leading to the cessation of suffering."

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 3 other places

Vol. 19 · Section 1707 — Tathasutta
Vol. 19 · Section 1708 — Lokasutta
Vol. 19 · Section 1706 — Mittasutta