A History of the Comma at Luke 23:43

For the punctuation marks in Luke 23:43, there are three possibilities: to put a comma before the word "today," to put it after "today," or to put a comma both before and after "today."--See "Understanding and Translating 'Today' in Luke 23.43," by J. Hong, published in "The Bible
 Translator," Vol. 46, 1995, pp. 408-417.
http://journals.sagepub.com/doi/abs/10.1177/026009439504600402?journalCode=tbtd

Early Greek manuscripts normally had no punctuation marks, but sometimes it is found in some manuscripts, as is the case with B (the Vatican 1209 uncial) which has a lower point (hypostigme) after semeron. Regarding the punctuation used by this MS, it was noted that in general "B has the higher point as a period, the lower point for a shorter pause." (A. T. Robertson, "A Grammar of the  Greek New Testament," p. 242)

The Vatican 1209 mss also uses punctuation marks in other places such as at Romans 8:5, ABCL and 26 cursives have a point after sarka.

The Curetonian Syriac (fifth century C.E.) renders Luke 23:43: "Amen, I say to thee to-day that with me thou shalt be in the Garden of Eden.'"--F. C. Burkitt, "The Curetonian Version of the Four Gospels," Vol. I, Cambridge, 1904.

Below are quotes from several Greek sources, transliterated with an accompanying English translation.

Tines men houtos anaginoskousin* _Amen lego soi semeron_ kai hypostizousin eita epipherousin, hotiet' emou ese e to paradeiso._("Some indeed read this way: 'Truly I tell you today,' and put a comma; then they add: 'You will be with me in Paradise.'"--Hesychius of Jerusalem, an ecclessiastical writer who died about 434 C.E. Greek text found in Patrologia Graeca, Vol. 93, columns 432, 1433.

Alloi de ekbiazontai to rhema, stizontes eis to <<Semeron,>> hin' e to legomenon toiouton* <<Amen ego soi semeron*>> eita to, <<met' emou ese en to paradeiso,>> epipherontes. ("But others press upon the saying, putting a punctuation mark after 'today,' so that it would be said this way: 'Truly I tell you today'; and then they add the expression: 'You will be with me in Paradise.'")--Theophylact, an ecclessistical writer who died about 1112 C.E. Edition: Patrologia Graeca, Vol. 123, column 1104.

alloi -- to rheton ekbiazontai* legousin gar dein hypostizontas (254: hypostizantas) anaginoskein* amen lego soi semeron*>> eith' houtos epipherein to* met' emou ese etc. ("Others press upon what is spoken; for they say it must read by putting a comma thus: 'Truly I tell you today,' and then adding the expression this way: 'You will be with me' etc.")--Scholia 237, 239, 254. Text found in Novum Testamentum Graece, editio octava critica maior, by C. Tischendorf, Vol. I, Leipzig, 1869, under Luke 23:43.

kai eutys eipen moi hoti amen amen semeron lego soi, met' emou ese en to parad[eiso]. ("And immediately he said to me: 'Most truly today I tell you, You will be with me in Paradise.'")--Descent into Hades, an apocryphal writing of the fourth century C.E. Text found in Novum Testamentum Graece, editio octava critica maior, by C. Tischendorf, Vol. I, Leipzig,869, under Luke 23:43.

ho de eipen auto* semeron lego soi aletheian hina se ekho eis ton parad[eison] met' emou. ("And he said to him: 'Today I tell you the truth, that I should have you in Paradise with me.'")--Gospel of Nicodemus (=Acts of Pilate)b287, an apocryphal writing of the fourth or fifth century C.E. Text found in Novum Testamentum Graece, editio octava critica maior, by C. Tischendorf, Vol. I, Leipzig, 1869, under Luke 23:43.

In conclusion, at least from the 4th century. until well into the 12th century. there were readers who understood the text at Luke 23:43 as "Truly I tell you today, You will be with me in Paradise."