Exegesis:

kai idou ‘and behold,’ focussing the attention strongly on what follows, cf. on 1.20.

andres duo sunelaloun autō ‘two men were talking with him,’ durative imperfect. For sullaleō cf. on 4.36.

hoitines ēsan Mōüsēs kai Ēlias ‘who were Moses and Elijah’; relative clause instead of apposition is more emphatic.

(V. 31) hoi … elegon tēn exodon autou ‘who … spoke about his departure,’ relative clause which has Mōüsēs kai Ēlias as its antecedent. It takes up sunelaloun autō in v. 30 and specifies the subject of the conversation.

exodos ‘departure,’ here euphemistically, ‘passing away,’ ‘death.’

ophthentes en doxē lit. ‘having appeared in glory,’ aorist tense, referring to an event which, in temporal sequence, precedes v. 30. For ophtentes cf. on 1.11; for en doxē cf. on v. 29.

hēn ēmellen plēroun en Ierousalēm ‘which he was to fulfil in Jerusalem.’ ēmellen means here ‘he was destined.’ 1.c.δ. For plēroō cf. on 1.20. Its use here implies that Jesus’ death is in some way a fulfilment of his mission.

Translation:

Talked with him, often a reciprocal form of ‘to speak.’

Moses and Elijah. One may have to add titles, e.g. ‘prophet,’ and/or indicated that the reference is to persons that are no longer among the living.

(V. 31) Who appeared in glory, or, as a new sentence, ‘they, or, these (two) men, had appeared in glory.’ If the linguistic sequence has to parallel the sequence of events, the clause must be shifted, e.g. ‘two men had appeared in glory; these were M. and E. They were talking with him, and spoke of….’ Appeared, or, ‘made their appearance,’ ‘showed themselves.’

His departure, which he was to accomplish at Jerusalem may have to be adjusted rather radically, e.g. ‘the death of Jesus which he had-to die in J.’ (Kituba), ‘his last days, how he would take death in J.’ (Sranan Tongo), “his departure, the destiny he was to fulfil in J.” (New English Bible); or more explicitly expressing the implication of Gr. plēroō, ‘his dying there in J., for that was the whole purpose for which God sent him’ (Tboli), “how he would soon fulfil God’s purpose by dying in J.” (Good News Translation); or again, shifting from verbal noun to verb, ‘how he would depart/die, as (or, something that) he was destined to do in J., or, which was the task he had to perform in J.’— His departure. Some other euphemisms for ‘death’ used are, ‘his end’ (Toraja-Sa’dan), ‘his last going/journey’ (Bahasa Indonesia KB), ‘his going-home’ (Balinese), ‘he will go-away’ (Pohnpeian, similarly Uab Meto). Often, however, one must simply say, ‘his dying’ (Tboli), ‘his future death’ (Tae,’ Ekari). Which he was to accomplish, or, ‘to fulfil,’ “to go through with” (An American Translation), “to achieve” (The Four Gospels – a New Translation), verbs that often do not go naturally with ‘departure,’ or, ‘death,’ because they imply activity and initiative on the part of the subject not compatible with the concept ‘dying’; hence adjustments are usually necessary, see above.

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.