In the phrase his disciples, the pronoun his refers back to Jesus. In many languages it may be necessary to make this fact specific, that is, “Jesus’ disciples,” since in the discourse the blind man is the last person mentioned.

Asked him is literally “asked him, saying.” The participle “saying” is merely a means of introducing direct discourse in Semitic Greek, and modern English translations omit it from the text.

Teacher is literally “rabbi” (see 1.38).

This verse reflects the Jewish belief that every illness was due to someone’s sin. Generally, if a man was born with some deformity, his condition was attributed to a sin his parents had committed. However, certain rabbis taught that it was possible for a baby to sin while still in its mother’s womb, and that belief is also reflected here. In Greek whose sin was it that caused him to be born blind? Was it his own or his parents’ sin? is literally “who sinned, this man or his parents, in order that he should be born blind?” Good News Translation reorders the elements in the question and divides them into two questions, thus simplifying the passage for the reader.

The question posed by Jesus’ disciples may cause difficulties in some languages, owing to the necessity of indicating clearly the relation between the person presumed to have sinned and the causing of the man to be born blind. The idea of sin causing blindness is fairly widespread in the world, but the grammatical ways in which this idea may be expressed differ considerably. In some languages one may say “Why was this man born blind? Was it because he sinned or because his parents sinned?” or “Who caused this man to be born blind? Was it because he himself sinned or because his parents sinned?” or “What caused this man to be born blind? Was it the evil which he did or was it the evil which his parents did?”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on the Gospel of John. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .