Exegesis:
diastasēs hōsei hōras mias lit. ‘when about one hour had passed,’ genitive absolute.
diistamai (also 24.51) ‘to go away,’ ‘to part,’ here ‘to pass,’ of time.
allos tis ‘somebody else,’ synonymous with heteros in v. 57.
diischurizeto legōn ‘affirmed strongly, or confidently, saying.’ legōn is used to introduce direct speech.
diischurizomai ‘to affirm strongly.’ It does not imply a reference to a previous statement.
ep’ alētheias ‘verily,’ ‘without doubt,’ cf. on 4.25.
kai houtos met’ autou ēn ‘this man was with him too,’ cf. on v. 56.
kai gar Galilaios estin ‘for he is a Galilean,’ best understood as an additional indication that Peter belonged to Jesus, cf. The Four Gospels – a New Translation.
Translation:
After an interval of about one hour, or, ‘about an hour later.’ Hour refers here to 1/12 of the period of daylight, but the exact duration is not to be pressed. Toraja-Sa’dan uses ‘one betel chewing,’ an idiomatic expression for an unspecified period of time which in actual fact is rather shorter than an hour.
Still another, or, ‘another (or, a second) man’; cf. on v. 58.
Insisted, or, ‘made himself strong’ (Uab Meto), ‘spoke emphatically/heavily’ (Ekari, Trukese); or simply, ‘said,’ since the idea of strong affirmation is sufficiently expressed in the following direct discourse.
Certainly, or, more adapted to the present context, “of course” (New English Bible), “there isn’t any doubt that” (Good News Translation), ‘right indeed’ (Bahasa Indonesia KB); and cf. references on “truly” in 4.24.
He is a Galilean, or, ‘he is a Galilee-man, or, one-who-hails-from Galilee’ (Balinese, here and in 23.6 respectively), ‘he is from Galilee,’ ‘Galilee is his (native) country.’ The statement probably is a deduction from what the man heard, i.e. Peter’s Galilean accent (cf. Mt. 26.73); this is of importance where one has to decide which evidential aspect is to be used (cf. on v. 56).
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.