Exegesis:

paralabōn de tous dōdeka ‘and after taking aside the twelve,’ i.e. taking them away from the other people around them, in order to talk to them privately.

idou anabainomen eis Ierousalēm ‘see, we are going up to Jerusalem.’ idou (cf. on 1.20) does not primarily focus the attention on anabainomen (which denotes a fact well known since 9.51) but on telesthēsetai etc. For anabainō cf. on 2.4.

kai telesthēsetai panta ta gegrammena dia tōn prophētōn tō huiō tou anthrōpou ‘and (when we are there) all that has been written through the prophets about the Son of man will be accomplished.’ For teleō cf. on 2.39. Here the idea of fulfillment is also implied. dia tōn prophētōn depicts the prophets as transmitters of a divine message of which God is the author. The dative tō huiō tou anthrōpou (cf. on 5.24) may go with telesthēsetai (cf. New English Bible), or with gegrammena (cf. Revised Standard Version), preferably the latter.

Translation:

Taking, i.e. ‘taking aside,’ suggesting that they remained in the same place, or, ‘taking with him’ (cf. on 9.10), implying that they moved along with Jesus.

For the twelve see on 8.1, and for going up on 2.4.

Everything that is written … by the prophets, or, ‘through the agency of the prophets’ (Marathi): or, ‘everything that is written … in (or, stands in, or, forms the contents of) the books of the prophets.’ In cases like this however, the difference between primary and secondary agency is negligible; hence, renderings like Revised Standard Version and ‘all that the prophets wrote…’ (Yao). For equivalent formulas cf. also on “as it is written” in 2.23.

Will be accomplished, or ‘fulfilled’ (cf. on 4.21), ‘will become a fact’; or transposing the first part of the clause, ‘everything will happen exactly in accordance with what (or, as it) is written in….’

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.