This question is about translation/interpretation of gita 3.17. The verse and some translations can be found here.
यस्त्वात्मरतिरेव स्यादात्मतृप्तश्च मानवः। आत्मन्येव च सन्तुष्टस्तस्य कार्यं न विद्यते।।3.17।।
Most of the translators, translate Atman as Self in English or AtmA in Hindi. For example -
English Translation By Swami Sivananda
3.17 But for that man who rejoices only in the Self, who is satisfied with the Self and who is content in the Self alone, verily there is nothing to do.
However, one translator, Swami Ramsukhdas, translates Atman as one-self (Hindi अपने-आप). His translation is -
Hindi translation by Swami Ramsukhdas
।।3.17।। जो मनुष्य अपने-आपमें ही रमण करनेवाला और अपने-आपमें ही तृप्त तथा अपने-आपमें ही संतुष्ट है, उसके लिये कोई कर्तव्य नहीं है।
(This translation coincides with my own understanding of the verse. This translation also appears more natural to me in the context of speaking about a person of contentment. However, the detailed interpretation given by the Swami treats Atman as more akin to Self, but that is not my concern here).
So the translation of my interest would be -
But for that man (woman) who rejoices only in himself (herself), who is satisfied with himself (herself) and who is content in himself (herself) alone, verily there is nothing to do.
Translated in this sense, the verse, by itself, has no supernatural implications like the pre-supposition of the existence of an eternal principle called Atman (which may or may not be your true nature, depending on which vedanta or astika school you may follow or not follow).
I do not know if there is anything in Sanskrit grammar that would prevent such a translation as given above (based on the one by Swami Ramsukhdas). I have two questions -
As far as this particular verse alone is concerned, is there any reason (either given by commentators or from Sanskrit grammar) for preferring to translate/interpret Atman as Self (an eternal supernatural principle), rather than as one-self (simply referring to the colloquial oneself)?
Has any ancient or medieval commentator explained this verse by interpreting Atman as one-self?
Note I understand that for advaita vedanta, one's own individual self is the same as Supreme Self. This is not what I am looking for, and my question has nothing to do with this. Further, by one-self, I am not referring to jIvAtman, which is another supernatural entity.