Four basic principles of paying attention to perfection

"Watching over In-and Out-breathing" practiced and developed, brings the four basic principles of Paying attention to perfection; the four fundamentals of attentiveness, practiced and developed bring the seven
Elements of Enlightenment to perfection; the seven elements of enlightenment, practiced and developed, bring Wisdom and Deliverance to perfection.

But how does Watching over In-and Out-breathing, practiced and developed, bring the four Basic principle of Paying Attention to Perfection?

I. When you are  conscious in making a long inhalation or exhalation, or in making a short inhalation or exhalation, or train yourself to inhale or exhale while feeling the whole [breath]-body,  or whilst calming down this bodily function-at such a time you are dwelling in "contemplation of the body," of energy, clearly conscious, attentive, after subduing worldly greed and grief. For, inhalation and exhalation I call one amongst the material phenomena.

2. When you train yourself to inhale or exhale as feeling rapture, or joy, or the mental functions, or whilst
calming down the mental functions-at such a time you are dwelling in "contemplation of the feelings," full of energy, clearly conscious, attentive, after subduing worldly greed and grief. For, the full awareness of in-and out breathing I call one amongst the feelings.

3. When you  train yourself to inhale or exhale whilst feeling the mind, or whilst gladdening the mind or whilst
concentrating the mind, or whilst setting the mind free-at such a time you are dwelling in "rumination of the mind," full of energy, clearly conscious, attentive, after subduing worldly greed and grief. For, without attentiveness and clear consciousness, I say, there is no Watching over in-and Out-breathing.

4. When you  train yourself to inhale or exhale whilst contemplating impermanence, or the fading away of passion, or extinction, or detachment at such a time you are dwelling in "contemplation of the phenomena," full of energy, clearly conscious, attentive, after subduing worldly greed and grief.

Watching over In-and Out-breathing, thus practiced and developed, brings the four Fundamentals of Attentiveness to perfection.

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