Exegesis:

hupokritai ‘you hypocrites’ (cf. on 6.42). The word implies here that they only pretend not to know how to interpret the present time.

to prosōpon tēs gēs kai tou ouranou ‘the appearance of the earth and the sky.’ Here prosōpon refers to signs that forecast changes in the weather.

oidate dokimazein ‘you know to interpret (correctly).’ For this use of oida cf. on 11.13.

dokimazō (also 14.19) ‘to examine,’ ‘to interpret,’ here with the connotation of interpreting correctly.

ton kairon de touton pōs ouk oidate dokimazein ‘but how (is it possible that) you do not know to interpret this present time?’ ton kairon touton is strongly emphatic. kairos refers here to the time in which God is acting, now in Jesus.

Translation:

You hypocrites, see 6.42.

You know how to, or, ‘you can,’ ‘you are able to.’

Interpret …, or analytically, ‘recognize the meaning of…’ (Kele), ‘understand/explain/discover what … means.’ Often specific verbs are available, e.g. ‘recognize-the-signs-of’ (Trukese, similarly Balinese), ‘judge-after-observation’ (Tzeltal).

Appearance of earth and sky, or, ‘face of earth and sky’ (East Nyanja, Yao), ‘shape (lit. circuit) of-sky together-with earth’ (Toraja-Sa’dan, the first part being a standing phrase to which ‘earth’ has been joined); or more analytically, ‘the things that appear on…,’ ‘what earth and sky show, or, give you to see,’ ‘what you see on earth (lit. underneath) and what you see in the sky’ (Shona 1966); cf. also, “you can look at the earth and the sky and tell what it means” (Good News Translation). Earth and sky. The reverse order may be obligatory or preferable, e.g. in Kele.

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.