αρα ουν αδελφοι στηκετε και κρατειτε τας παραδοσεις ας εδιδαχθητε ειτε δια λογου ειτε δι επιστολης ημων [Stephanus TR 1550]
Therefore, brethren, stand fast, and hold the traditions which ye have been taught, whether by word, or our epistle. [2 Thess 2:15 KJV]
The Englishman's Greek New Testament (1870) translates this as 'whether by word or by our epistle'.
Young's Literal has 'whether through word, whether through our letter'.
The original seems to me to state :
whether by word whether by epistle of us.
In which case it seems to me that 'of us' relates both to 'whether by word' and also to 'whether by epistle'.
This has important bearing as to whether the 'word' is also the apostle's word (no longer available nowadays) or whether 'word' means 'the word of other than apostles'.
If the former, then we are dependent only on the epistles (which will convey both the content and the tenor of the 'word' which we can no longer access) or whether we are required to search out documentation (other than the apostolic epistles) in order to be fully aware of what Paul calls 'the traditions' (verse 15), of which we are to 'hold fast'.
The later use of the word 'tradition', 3:6, makes the reference, in that particular place, specific to only 'us'.
Am I correct in my reading 'of us' as applying, grammatically, to both the preceding 'word' and 'epistle' ?