Exegesis:

autos de ‘but he,’ emphatic.

eidōs autōn ta dianoēmata ‘knowing their thoughts,’ i.e. understanding what really was behind their utterances in vv. 15f.

dianoēma ‘(inner) thought.’

eipen autois ‘said to them.’ autois is best understood as referring both to tines (v. 15) and heteroi (v. 16).

pasa basileia eph’ heautēn diameristheisa ‘every kingdom divided against itself,’ i.e. the composing parts are divided against one another, rather than against the kingdom as a whole. Hence renderings like ‘disunited’ (cf. An American Translation), or ‘internally divided’ (cf. Brouwer).

diamerizō ‘to divide,’ both in a literal and in a figurative sense, ‘to separate,’ ‘to distribute.’

erēmoutai ‘is ruined,’ ‘becomes desolate.’

kai oikos epi oikon piptei ‘and (as a result) house falls on house,’ or, with diameristheis understood, ‘and house, i.e. family, divided against house falls,’ preferably the former.

Translation:

To know, i.e. ‘to be aware of,’ ‘not to be ignorant about’ (Javanese).

Their thoughts, cf. on 6.8.

Every kingdom divided against itself is laid waste, or, ‘every kingdom that is-divided, fighting the one the other, will be broken’ (Sranan Tongo), “kingdoms are brought to ruin by internal strive” (The Four Gospels – a New Translation).

And, resultative, ‘so that.’

House falls upon house, or e.g., ‘the houses collapse, fall on each other’ (Balinese, similarly Bahasa Indonesia RC).

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.