So I have heard.
At one time the Buddha was staying near Sāvatthī in Jeta’s Grove, Anāthapiṇḍika’s monastery.
Now at that time Venerable Mahākaccāna was sitting not far from the Buddha, cross-legged, with his body straight and mindfulness of the body well-established internally in his presence.
The Buddha saw him meditating there.
Then, understanding this matter, on that occasion the Buddha expressed this heartfelt sentiment:
“Their mindfulness would always
be established in the body, constant:
‘It might not be, and it might not be mine,
It will not be, and it will not be mine.’
Meditating stage by stage on that,
in time they’d cross over clinging.”