Exegesis:

hoti oikodomeite ta mnēmeia tōn prophētōn ‘for you build the tombs of the prophets.’ The present tense of oikodomeite is best understood as habitual. mnēmeion means here ‘tomb,’ ‘memorial,’ elsewhere in Luke (e.g. v. 44) ‘grave.’

Translation:

Build the tombs of the prophets, or, ‘build tombs for the prophets.’ Where ‘tombs’ in the sense of ‘sepulchral monuments’ are unknown, one may say ‘make beautiful the graves of…’ (Sranan Tongo), ‘erect/make a building (or, put high stones) where the prophets have been buried.’

Whom your fathers killed, or better to bring out the contrast, “the very prophets your ancestors murdered” (Good News Translation).

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.