Matthew Poole and continuators on John 9:18

18 But the Jews did not believe concerning him, that he had been blind, and received his sight, until they called the Parents of him that had received his sight .

That is, The Rulers of the Iews did not, or the Multitude, or Rabble of the Iews did not; for we before heard that many of the common Iews did, they had seen him for a long time sit begging; (begging being allowed, in that their corrupt and miserable state, they being Tributary to the Romans, tho in their setled prosperous state, there was such a liberal Provision made for their Poor, that there was no Beggar in Israel:) besides, they had it from his own mouth, ver. 9. but the Rulers had no mind to believe it; and many others of the Iews (possibly) had been no eyewitnesses of his begging, but had onely heard the relation from others: the Rulers therefore send for the Parents of the Blind-man.