John 9:22

These things said his parents, because they feared the Jews: for the Jews had agreed already, that if any man should confess him to be the Christ, he should be put out of the synagogue. Therefore said his parents, He is of age; ask him.

They feared the Jews ... This means fear of the Sanhedrin, a fear mentioned four times in John: here, and in John 7:13; John 12:42, and in John 19:38. Excommunication was the dreaded penalty by which the unscrupulous leaders enforced their will upon the people. They had marshaled the entire apparatus of hierarchical power against any acceptance of Christ by the multitude. To be cut off from all social, religious, and even business communication with the whole nation was a severe and dreaded penalty, and far more than enough to strike terror and apprehension into the hearts of simple people like the parents of the man born blind. One may sympathize with their fears without condoning their timidity.