Exegesis:
kai pantes emarturoun autō lit. ‘and all bore witness for him.’
martureō with dative ‘to bear witness to’ (cf. Jn. 3.26), may here mean either ‘to speak well of’ (cf. Revised Standard Version, Translator’s New Testament, An American Translation, more freely also New English Bible, Williams), or ‘to approve of’ (Brouwer, cf. “to be well impressed with”, Good News Translation). The latter is preferable.
epi tois logois tēs charitos tois ekporeuomenois ek tou stomatos autou ‘at the words of grace coming from his mouth.’ charis is best understood as ‘graciousness.’ tēs charitos is a genitive of quality. tois ekporeuomenois ek tou stomatos autou ‘coming from his mouth’ reflects common usage in the Septuagint, cf. e.g. Num. 32.24; Deut. 8.3 (quoted in Mt. 4.4). The idiom seems to imply that the words spoken are, as it were, a part of the speaker, revealing what is in him, or binding him to the word he has spoken. Here the words that came from Jesus’ mouth are representative of his personality.
kai elegon ‘and they said,’ iterative imperfect.
ouchi huios estin Iōsēph houtos ‘is not this Joseph’s son?’ This question expresses either astonishment at the fact that Joseph’s son had become such a fine preacher or indignation at his presumption of speaking as a prophet, probably both. houtos may express contempt or amazement.
ouchi as an interrogative particle indicates that an affirmative answer is expected.
Translation:
Spoke well of him, preferably, ‘expressed their approval of him,’ ‘said, “he is right!”, or, “His words are true!” ’
Wondered at, see on 1.21.
Gracious words, or, “winning words” (An American Translation), ‘sweet words’ (Malay); or ‘the loveliness (lit. fragrance), or, the eloquence (lit. smoothness) of his words’ (Javanese, Balinese), ‘how graciously he spoke.’
In some cases the clause which proceeded out of his mouth can be rendered rather literally, e.g. in Tboli, which has, ‘they were all completely absorbed in the things-told which dropped from his mouth.’ In several receptor languages, however, idiom and/or decodability require another rendering, such as ‘which fell/came from his lips,’ ‘which flowed from in his mouth’ (Pohnpeian), ‘that he uttered/spoke.’ Neither the literal nor the other renderings express the specific shade of meaning discussed in Exegesis. This does not mean a serious loss of information here, since the context makes it clear that the words were taken to be characteristic of Jesus’ personality.
Is not this Joseph’s son. If the receptor language cannot use an interrogative sentence in this sense, an affirmative sentence must express the astonishment or indignation of the speakers, e.g. ‘and he merely is J’s son,’ or, ‘this fellow is nothing more than a son of J..’
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.