Exegesis:

prōton de ‘but first,’ i.e. before it comes to that. For the rest of this verse cf. on 9.22. genea means ‘generation’ and refers here to Jesus’ contemporaries.

Translation:

This generation (corresponding to “the elders and chief priests and scribes” in the parallel verse 9.22a) is virtually identical with “the men of this generation” in 7.31, which see.

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.