Exegesis:

ti de kai aph’ heautōn ou krinete to dikaion ‘why then (is it) not of yourselves (that) you judge what is right?’ de kai serves to emphasize aph’ heautōn.

aph’ heautōn ‘of yourselves,’ i.e. ‘out of your own judgment,’ contrasting with the external signs of the time, or with being taught by Jesus or somebody else, preferably the latter.

to dikaion ‘what is right,’ i.e. ‘what you ought to do.’ It refers to the implication of vv. 58f (see below).

Translation:

You judge for yourselves, or, ‘you yourselves decide,’ ‘you take your own decision.’ The verb is used here in a non-legal context, but it anticipates the example given in v. 58, which is in a legal sphere; hence a term that is appropriate in both spheres is preferable, such as e.g. ‘to weigh/consider’ (Javanese), ‘take/give a decision’ (cf. Bahasa Indonesia).

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.