τίπτε μοι, Ἑρμεία χρυσόρραπι, εἰλήλουθας,
αἰδοῖός τε φίλος τε; πάρος γε μὲν οὔ τι θαμίζεις.
αὔδα ὅ τι φρονέεις· τελέσαι δέ με θυμὸς ἄνωγεν,
εἰ δύναμαι τελέσαι γε καὶ εἰ τετελεσμένον ἐστίν.
Hainsworth, the Oxford commentary to the Odyssey:
Other commentaries interpret this a bit differently, e.g. Merry-Riddell:τετελεσμένον: a nuance of meaning must be added to the pf. ptcp. similar to that conveyed by the adjectival formant -τός: "something that must come to pass".
Other commentaries, Ameis-Hentze-Cauer and Stanford, interpret this similarly, i.e. that τετελεσμένον expresses the possibility of the thing happening, not a certitude or a predestination à la Rutherford. Translators take it various ways, but Martin Hammond apparently follows Rutherford with "my heart prompts me to do it, if I can and it is to be". For me, this seems wrong, but what do you think?εἰ τετελεσμένον ἐστίν, "if it is a thing that ever hath been done", which would imply the possibility of its being done again. Nitzsch compares τἁ γενόμενα φανερὸν ὅτι δuνατά Arist. Poet. 9.6. The same transition in meaning is seen in the verbal adjective in -τος. Compare also τετελεσμένον ἔσται Il. 1.212, etc.
ὧδε γὰρ ἐξερέω, τὸ δὲ καὶ τετελεσμένον ἔσται Il. 1.212 is different because of the future tense ἔσται.