Exegesis:

euge, agathe doule ‘well done, good slave!,’ an expression of approval.

hoti en elachistō pistos egenou ‘because you have been faithful in a very small matter,’ cf. on 16.10 and 12.42. The clause indicates the cause of the following statement.

isthi exousian echōn epanō deka poleōn lit. ‘be having authority over ten towns,’ hence ‘have authority.’ For epanō cf. on 4.39; here it is used in a figurative sense.

Translation:

Well done, or some other exclamation of approval, e.g. ‘Splendid!’ (cf. Phillips).

Good servant, or, shifting from vocative to statement, ‘you are a good servant.’

You have been faithful in a very little, or, ‘I know now that I can trust you in a very small matter’; and cf. on 16.10.

You shall have authority over. The imperative of the Greek can sometimes be preserved (e.g. in Sranan Tongo, ‘go to govern’), but in many languages one must use an indicative (cf. Revised Standard Version), e.g. ‘you (shall) have, or, I (shall) give you, the right to rule.’

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.