[proxy_user]

καὶ εἶπεν αὐτῷ· ἀμήν σοι λέγω, σήμερον μετ’ ἐμοῦ ἔσῃ ἐν τῷ παραδείσῳ

There would not have been a comma in the Greek punctuation system in this period. The comma after 'lego' was added later, based on the perceived sense of the sentence. However, there is a lot of ambiguity in the original sentence. It would have probably been more obvious to a native speaker of Koine, which means we should give some authority to the earliest added punctuation. Presumably, that would reflect how the verses were read aloud in the early churches.

[count-your-change]

Where that ambiguity exists because we do use commas and all the nuances of the koine’ Greek are not known, we can only rely on the whole of the Scriptures.

Where or if a comma is added will be determined by what the translator believes the meaning of Luke 23:42, 43 is.

[Alas Babylon!]

Well, it might have been more obvious to a speaker of Koine, but let's not forget that Jesus wasn't speaking Greek. He spoke Aramaic.

Any form of Greek citing Jesus’s words is a translation from Aramaic, except in those cases where He spoke Hebrew (Eloi, Eloi, Lama sambach thani!).

So to me, all this analysis of where a comma should go in Greek is like counting the angels dancing on a pin head.