That moment when you read in BDAG (and BAGD, too) that σκοτίζω’s middle form has the function of:

The passive of moral darkening.

That’s about as beautiful as some of Wallace’s (Greek Grammar Beyond the Basics) categories for case (especially the genitive ones). This particular instance seems to be an effort on the part of the editors to account for the fact that this instance of the verb takes a θη form in the perfective aspect and the verb itself is not ‘deponent’. If you can’t account for θη not actually being passive with the normal punt to deponency (which is a fancy word for ‘I don’t understand this’), I suppose making up an entirely new category for a single verb is the next best thing.

Update: So my good friend Stephen Carlson pointed out that the abbreviation ‘pass.’ in BDAG can also mean ‘passage’ rather than ‘passive’ and suggested that is the better reading here. Contextually, it makes more sense, but in terms of English grammar, that’s an incredibly odd use of the preposition ‘of’: “the passage of moral darkening.”

So maybe just bad English instead of bad linguistics–either way still a “wait what?” though.

Update to the Update: After more examination, I’m back to being convinced ‘pass.’ does indeed refer to ‘passive’. Consider the entry for βόσκω as evidence:

② to feed on herbage, graze, feed, pass. of livestock (Is 5:17; 11:7; Jos., Bell. 6, 153; SibOr 3, 789) ἀγέλη βοσκομένη Mt 8:30; Mk 5:11; Lk 8:32. πρόβατα βοσκόμενα (PTebt 298, 53) Hs 6, 2, 4, cp. 7; sim.

I looked up every single reference here. All involve middle forms of the verb. Every single one of them. So here’s a ‘passive of livestock.’

Update to the Update’s Update:

So ‘pass.’ does mean passive here, but there’s more going on than meets the eye. I’ve got a follow up on the way now.