The evangelist accounts for the reticence of the parents by their fear of consequences. These things said his parents, because they feared the Jews. This passage provides strong evidence of the technical use of the term "the Jews."
Doubtless these parents were Israelites, but they were not "Jews" in the Johannine sense. The "Jews" were the hierarchical and ecclesiastico-political authorities. For they had already come to the agreement (Luke 22:5; Acts 23:20; 1 Macc.
9:70); had mutually determined—it does not follow that the Sanhedrin had issued a public order, but that a formidable party of "Jews" had made a συνθήκη, had pledged each other and made it sufficiently known even to such persons as the poverty-stricken parents of the blind beggar, that it would be carried out by the adequate authority in such a matter—that if any man should confess that he was Christ ("he" ( αὐτὸν) is remarkable—it shows how full the thoughts of the evangelist were of the Personality of Jesus), he should be put out of the synagogue; or, become unsynagoqued.
The Talmud speaks of three kinds of excommunication (of. also Matthew 5:22), of which the first two were disciplinary; the third answers to complete and final expulsion (in 'Jeremiah Moed. K.,' 81, d, להקם לדבי אוה, Edersheim).
The general designation was shammata, from דמַשֱ, to destroy. The first form of it was called nesephah, and did not amount to more than severe rebuke. It would exclude from religious privileges for seven or thirty days, according to the dignity of the authority by whom it was pronounced (cf.
1 Timothy 5:1). The second form of shammata was called niddui, which lasted for thirty days at the least, and might be repeated at the end of them. If these admonitions failed to produce their right effect, it might lead to the third and final excommunication, called cherem, or ban, whose duration was indefinite.
The second of these forms was accompanied by blast of trumpet and terrible curses, which deprived the sufferer of all kinds of social intercourse. He was avoided as a leper; if he died, he was buried without funeral or mourning.
The cherem was even a more terrible anathema, and might last for life. The parents of the blind man might easily fear such a curse. The ban to which this blind man was eventually exposed did not prevent him from moving about the city.
The ban pronounced on Jesus led doubtless to the condemnation, issuing in his ignominy and trial for a capital offence. It was probably the second of the three forms of anathema to which he was ultimately condemned.
It was quite sufficient temptation for these poor parents to have preserved an obstinate reticence.