What are the different interpretations and translations and what might be the most correct interpretation according to the different lines of practice? How are they rationalized?
Here are some:
Etymology:
pari- is a prefix used with the connotation of around, about, all over, or that of completeness. Thus dhāvati means
'to run' and paridhāvati means 'to run about'; vajati - 'to go/
proceed' becomes paribbajati, 'to wander about', ie. 'to live the life
of a religious mendicant'; carati - 'to walk' becomes paricarati - 'to
walk around, ie. to serve, honour'; gaṇeti, 'to count' becomes
parigaṇeti - 'to calculate'.
mukhaṃ means primarily and literally 'mouth', by extension 'face' and
figuratively 'entrance', 'opening', 'brim', then in a more abstract
meaning 'the front', 'the foremost' and finally 'that which is an
entrance into something', ie. 'a mean', 'a cause'.
Strictly from the point of view of semantics (ie. neglecting
contextual information), the following meanings could reasonably be
derived from the juxtaposition of these two components: around the
mouth, all over the mouth, completely on the mouth, around the face,
all over the face, completely on the face, around the entrance, all
over the entrance, completely on the entrance, around the front, all
over the front, completely on the front
Note: The above link also has references to commentaries & later Pāḷi literature.
Thanissaro Bhikkhu:
To the fore (parimukhaṃ): The Abhidhamma takes an etymological
approach to this term, defining it as around (pari-) the mouth
(mukhaṃ). In the Vinaya, however, it is used in a context (Cv.V.27.4)
where it undoubtedly means the front of the chest. There is also the
possibility that the term could be used idiomatically as "to the
front," which is how I have translated it here.
Ānandajoti Bhikkhu:
Parimukhaṃ means at the front, or perhaps, around the mouth, i.e. it
is a vague area, not meant to be confined to one particular spot or
place, which would have been easy to designate if that is what was
meant (like specifying oṭṭha, the lip). It is of course the
mindfulness that is important in the practice, not the breathing as
such, which only provides a basis for the mindfulness.
Anālayo Bhikkhu:
Once the posture is set up, mindfulness is to be established “in
front”. The injunction “in front” (parimukhaṃ) can be understood
literally or figuratively. Following the more literal understanding,
“in front” indicates the nostril area as the most appropriate for
attention to the in- and out-breaths. Alternatively, “in front”
understood more figuratively suggests a firm establishment of sati,
sati being mentally “in front” in the sense of meditative composure
and attentiveness.
Sujato Bhikkhu:
In the gradual training, sati and upatthana occur together in the
common idiom parimukhaṃ satim upatthapeti. Here the term parimukha is
one of those simple words that is so hard to interpret. It modern
renderings usually use something vague like 'in front'. However the
phrase frequently occurs in contexts outside of anapanasati, making
the interpretation 'at the nose-tip', or any literal spatial
interpretation, unlikely. The Sanskrit has a different reading,
pratimukha. This has many meanings, among which are 'reflection' and
'presence'. Both of these would be appropriate in meditative context.
But the word usually, as here, occurs in close conjunction with
upatthana, which also means 'presence'. I think here we have another
example of that common feature of Pali or Sanskrit, a conjunction of
synonyms for emphasis: literally, 'one makes present a presence of
presence of mind', or more happily, 'one establishes presence of
mindfulness'.
S. N. Goenka: The awareness is established around the mouth,
the entrance to the nostrils: parimukhaṃ. Certain traditions
translate this as "in the front," as if the awareness is imagined to
be in front of the person, but this sets up a duality. Actually you
have to feel the breath coming and going around the mouth, above the
upper lip, which is parimukhaṃ.
Additional References: