Exegesis:

plēn ‘but,’ cf. on 6.24. Here its use suggests that v. 33 is no longer part of the message to Herod.

dei me sēmeron kai aurion kai tē echomenē poreuesthai ‘I must continue my journey today and tomorrow and the next day.’ poreuesthai refers to the journey to Jerusalem. sēmeron kai aurion kai tē echomenē refers to the same time as the partly identical partly synonymous words in v. 32.

hē echomenē, scil. hēmera ‘the immediately following day.’

ouk endechetai prophētēn apolesthai exō Ierousalēm ‘it is impossible that a prophet should perish outside Jerusalem.’

endechetai ‘it is possible,’ ‘it is right,’ ‘it is thinkable.’

Translation:

Nevertheless, or, ‘however,’ ‘yet.’ To mark the message to Herod as ended, The Four Gospels – a New Translation has, “yet to you I admit that”.

I must, see 2.49.

The day following, or, ‘the day-after-tomorrow’ (Sranan Tongo, lit. ‘the-other tomorrow’; also several Indonesian languages), in some cases coinciding with the rendering of ‘the third day’ in v. 32.

Away from, or, “anywhere except in” (Good News Translation), ‘if not in’ (Bahasa Indonesia 1968), ‘in any other place than’ (Sranan Tongo), focussing on what must happen in Jerusalem, rather than on what cannot happen outside it (a meaning conveyed by some literal renderings).

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.