Exegesis:
kai ērxanto dialogizesthai hoi grammateis kai hoi Pharisaioi ‘and the scribes and the Pharisees began to question.’ For ērxanto cf. on 4.21; here it expresses that the questioning was a reaction to what Jesus did. For dialogizomai cf. on 1.29. Here two interpretations are possible, i.e. (1) that they began to debate or to argue among themselves, and (2) that they wondered in their own minds. Interpretation (1) appears to be preferable.
grammateus ‘expert in the law,’ cf. on v. 17.
tis estin houtos hos lalei blasphēmias lit. ‘who is he who speaks blasphemies,’ with a note of contempt and indignation, hence “who is this fellow with his blasphemous talk” (New English Bible), the relative clause hos lalei blasphēmias serving to indicate the cause of the indignation.
blasphēmia ‘blasphemy’ i.e. impious talk about or concerning God. The plural here has no special meaning. blasphēmias lalein is synonymous with blasphēmein (Mk. 2.7).
tis … ei mē monos ho theos ‘who … but only God,’ a combination of two phrases i.e. tis … ei mē ‘who but,’ and monos ho theos ‘God alone,’ which reinforce one another.
Translation:
Scribe (also in 5.30; 6.7; 9.22; 11.53; 15.2; 19.47; 20.1, 19, 39, 46; 22.2, 66; 23.10), or ‘one who knows the scriptures’ (Uab Meto), or, ‘studies/interprets the scriptures,’ ‘scholar of the law’ (colloquial Japanese). Terms existing in the culture for ‘teacher of religion,’ ‘religious scholar,’ such as, ‘bearer-of-the-law’ (Sinhala), ‘one-learned-in-the-Scriptures’ (Marathi) may be used, where necessary with a further qualification, e.g. of ‘Moses,’ or, ‘Jewish.’ In some countries with a Muslim background Arabic terms, such as ulama/ulema, katib, fakih, have been used but proved unsatisfactory. Renderings as, ‘one who writes,’ ‘one skilled in writing,’ ‘a book-knower,’ ‘a book-wise person,’ are acceptable where differentiation of function is unknown and such an expression refers to a position of learning comparable to that of the scribes, but in other circumstances a more specific term or phrase is preferable. In the New Testament ‘scribe’ and ‘lawyer’ (cf. on 7.30) are never used in the same sentence; therefore the two synonyms can acceptably be rendered by one expression, as done e.g. in Marathi; elsewhere ‘scribe,’ ‘lawyer’ and ‘teacher of the law’ (5.17) are rendered by one and the same term, as done e.g. in Shona 1966 (‘expert of the law’), Balinese (‘expert of the books of Torah’), Ekari (‘one knowing paper/book’), Tboli (‘one who taught the law God before caused Moses to write,’ which in further occurrences in the same passage is shortened to ‘one who taught the law of Moses’).
The function of began may be rendered here by a transitional such as ‘thereupon.’
To question, or, ‘to make objections,’ ‘to deliberate’ (Santali), ‘to consider (etym. to weigh)’ (Bahasa Indonesia), all referring both to thought and to discussion. Where such happy ambiguity is not possible the translator following interpretation (1) has to choose a term referring to audible debate or discussion, for which cf. also “they said to one another” in 4.36. In honorific languages this will imply the use of polite terms common between persons who are colleagues but probably not intimates.
Who is this…? The interrogative clause, expressing the indignation felt by the scribes and Pharisees, may require modal forms, e.g. ‘who possibly this one?,’ ‘who can this be?’; or in affirmative clause ‘I shall not allow this fellow to speak….’
Speaks blasphemies, or, ‘blasphemes.’
Who can forgive sins but God only, or shifting to the affirmative, “no man can forgive sins; God alone can” (Good News Translation). If the person forgiven has to be mentioned, one may say, ‘who can forgive man’s sins,’ ‘who can forgive us our (inclusive) sins’ (Huautla Mazatec). If God had to be mentioned as agent in v. 20, one may say here something like, ‘only God can declare that he has forgiven people’s sins.’
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.