Aṅguttara Nikāya,
Catukkanipātapāḷi
Satipaṭṭhānasuttaṃ
AN4.274
'Of passion, almsmen, for the comprehension, four principles should be cultivated.
Which four?
Here, almsmen, an almsman looking at the body, dwells in the body; as the ardent aware recollector would remove the avarice and distress about the world.
Looking at feelings, he dwells in feelings; as the ardent aware recollector would remove the avarice and distress about the world.
Looking at mind, he dwells in mind; as the ardent aware recollector would remove the avarice and distress about the world.
Looking at principles, he dwells in principles; as the ardent aware recollector would remove the avarice and distress about the world.
Of passion, almsmen, for the comprehension, these four principles should be cultivated.'