And how does a mendicant meditate observing an aspect of feelings?

It’s when a mendicant who feels a pleasant feeling knows: ‘I feel a pleasant feeling.’

When they feel a painful feeling, they know: ‘I feel a painful feeling.’

When they feel a neutral feeling, they know: ‘I feel a neutral feeling.’

When they feel a material pleasant feeling, they know: ‘I feel a material pleasant feeling.’

When they feel a spiritual pleasant feeling, they know: ‘I feel a spiritual pleasant feeling.’

When they feel a material painful feeling, they know: ‘I feel a material painful feeling.’

When they feel a spiritual painful feeling, they know: ‘I feel a spiritual painful feeling.’

When they feel a material neutral feeling, they know: ‘I feel a material neutral feeling.’

When they feel a spiritual neutral feeling, they know: ‘I feel a spiritual neutral feeling.’

And so they meditate observing an aspect of the feelings internally, externally, and both internally and externally. They meditate observing feelings as liable to originate, as liable to vanish, and as liable to both originate and vanish. Or mindfulness is established that feelings exist, to the extent necessary for knowledge and mindfulness. They meditate independent, not grasping at anything in the world.

That’s how a mendicant meditates by observing an aspect of feelings.