Exegesis:

legō gar humin ‘for I tell you,’ cf. on 3.8.

apo tou nun ‘from now on,’ i.e. after this time.

apo tou genēmatos tēs ampelou ‘from the fruit of the vine,’ i.e. from the wine that is in the cup.

genēma ‘product,’ ‘fruit.’

heōs hou hē basileia tou theou elthē ‘till the kingdom of God has come,’ cf. on 17.20.

Translation:

From now on … not … until, or, “not … again until” (An American Translation); or in two clauses, ‘I will not drink…; I will do it again only when’ (cf. Kekchi).

The fruit of the vine, or, ‘the product of the vine,’ ‘what the vine produces,’ or simply, ‘wine’ (for which cf. on 1.15, and references). What is drunk in church at the celebration of the Lord’s supper may influence the translator’s choice. For that reason he may, for instance, prefer a borrowed foreign term for ‘wine’ here to the cultural equivalent he uses in other texts. For vine see in the note on “vineyard” in 20.9.

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.