Exegesis:

kath’ hēmeran ‘daily,’ ‘day by day,’ with emphasis, going with the following absolute genitive.

ontos mou meth’ humōn en tō hierō ‘when I was with you in the temple.’ meth’ humōn does not imply personal contact. For hieron cf. on 2.27.

ouk exeteinate tas cheiras ep’ eme ‘you did not stretch out your hands against me,’ hence either ‘you did not lay hands on me’ (as a reference to an act), or, ‘you did not raise a hand against me’ (as an expression of hostile intent), preferably the latter.

all’ hautē estin humōn hē hōra ‘but this is your hour,’ meaning either ‘now at this time and this place you dare to arrest me,’ or ‘this is your appointed time,’ i.e. appointed by God. The latter is preferable.

kai hē exousia tou skotous ‘and (this is) the power of darkness,’ i.e., now the power of darkness is at work. For detailed interpretations of this clause and its relationship to hautē estin humōn hē hōra see commentaries. For translation purposes it seems advisable to understand the clause as expressing a complementary aspect of the situation: not only the hour of Jesus’ human adversaries but also of the activity of the power of darkness, i.e. of the devil.

Translation:

You did not lay hands on me, preferably, ‘you did not raise a hand against me,’ or, ‘you did not even try/dare to touch me’ (cf. Tae’ 1933). For the rendering of the phrase according to the other interpretation see on 20.19.

This is your hour, or more explicitly, ‘this is the moment for you to act,’ ‘now you are allowed (or, God allows you) to do this.’

And the power of darkness, i.e. ‘and (this is the moment) for the power of darkness to act,’ ‘it is also the time of darkness when it has strength’ (Shona 1966), parallel to the preceding phrase. Power of darkness, i.e. the powerful/mighty/strong one who is characterized as dark, or, where idiomatically preferable, the reversed construction, ‘the dark one who is powerful.’ If the phrase would not be understood as referring to the devil, such a reference has to be added, e.g. ‘the devil who rules in darkness.’

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.