With MahāmoggallānaMahāmoggallānasutta

So I have heard.Evaṁ me sutaṁ— At one time the Buddha was staying near Sāvatthī in Jeta’s Grove, Anāthapiṇḍika’s monastery.ekaṁ samayaṁ bhagavā sāvatthiyaṁ viharati jetavane anāthapiṇḍikassa ārāme. Now at that time Venerable Mahāmoggallāna was sitting not far from the Buddha, cross-legged, with his body straight and mindfulness of the body well-established in himself.Tena kho pana samayena āyasmā mahāmoggallāno bhagavato avidūre nisinno hoti pallaṅkaṁ ābhujitvā ujuṁ kāyaṁ paṇidhāya kāyagatāya satiyā ajjhattaṁ sūpaṭṭhitāya. The Buddha saw him meditating there.Addasā kho bhagavā āyasmantaṁ mahāmoggallānaṁ avidūre nisinnaṁ pallaṅkaṁ ābhujitvā ujuṁ kāyaṁ paṇidhāya kāyagatāya satiyā ajjhattaṁ sūpaṭṭhitāya.

Then, understanding this matter, on that occasion the Buddha expressed this heartfelt sentiment:Atha kho bhagavā etamatthaṁ viditvā tāyaṁ velāyaṁ imaṁ udānaṁ udānesi:

“With mindfulness of the body established,“Sati kāyagatā upaṭṭhitā, restrained in the six fields of contact,Chasu phassāyatanesu saṁvuto; a mendicant always immersed in samādhiSatataṁ bhikkhu samāhito, would know extinguishment in themselves.”Jaññā nibbānamattano”ti.