Exegesis:
kai egeneto thambos epi pantas ‘and astonishment came upon all.’ For a similar phrase cf. 1.65.
thambos (also 5.9) ‘astonishment,’ ‘awe,’ in the New Testament always of the feeling that comes over people when they witness an act of divine power.
kai sunelaloun pros allēlous ‘and they talked to one another.’ The imperfect tense has durative aspect.
sullaleō ‘to talk,’ ‘to talk with.’
tis ho logos houtos ‘what is this word?’ logos is best understood as referring to the imperatives of v. 35, ‘be silent and get out of him.’ This is supported by the fact that the subsequent clause introduced by hoti refers unequivocally to Jesus’ power over the unclean spirits.
hoti introducing a clause which describes what ho logos houtos refers to, either ‘because,’ ‘for’ (cf. Revised Standard Version, Translator’s New Testament, An American Translation, Brouwer, Nieuwe Vertaling) or ‘that,’ preferably the former.
en exousia kai dunamei ‘with authority and power.’ The former refers to what cannot be contradicted, the latter to what cannot be resisted (cf. Bengel quoted by Plummer).
epitassei tois akathartois pneumasin, kai exerchontai ‘he orders the unclean spirits and they come out.’ The latter of the two co-ordinate clauses describes what is the result of the former.
epitassō ‘to order,’ with the dative. Except 14.22 always of giving orders to more than human powers.
Translation:
For amazed see also above, on “wondered at” in 1.21.
Said to one another. Luke uses various phrases with reference to discussion or consultation taking place among Jesus’ general audience and/or his opponents (4.36; 5.21; 6.11; 20.5, usually in reaction to what they hear him say or see him do), or among the disciples (9.46; 22.23), or between the two men on the way to Emmaus (24.14f), or among the tenants in 20.14 and the shepherds in 2.15. The particular nuance of the discussion may be that of wonder or questioning (4.36; 22.23), indignation (5.21), controversy (9.46), planning (for arrest or murder, 6.11; 20.14), deliberation (20.5; 22.4; 24.14). Some languages possess various specific terms for some or all of these nuances, cf. English “discussion”, “dispute”, “debate”, “consultation”, “planning”, “argument”, “questionings” etc., but elsewhere one may have to use a more generic rendering, i.e. a reciprocal expression derived from or built upon ‘to say’ or ‘to ask,’ leaving the specific nuance to be expressed by the following indication of the contents of the discussion (often given in direct discourse) or to be inferred from the context. A corresponding reflexive expression (e.g. ‘to ask-one-self,’ ‘to say to the heart’) is in some of these languages used for inward reasoning and thought.
What is this word, or, ‘how can he speak like that.’ The interrogative clause has the force of an exclamation, cf. Bible de Jérusalem, quelle parole! and Balinese, which adds the exclamatory particle that indicates wonder.
One may have to make explicit that the relationship between the two next clauses is a consecutive one, e.g. ‘with such authority and power he commands … that they come out,’ or transposing the prepositional phrase, ‘he commands … with the result that they come out; so great is (or, that shows) his authority and power.’
With authority and power, or, ‘with (or, as one who has) the right and power (to speak).’ Sranan Tongo combines the two terms in one expression, cf. ‘in the was-of-a-boss he masters the bad spirits.’
He commands. If the verb must be rendered analytically and the contents of the command has to be specified, this may result in something like, ‘he tells the unclean spirits to come out (or, in direct discourse), and they do so.’
Unclean spirits, see references on “demon” in v. 35.
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.