John 9:28

And they reviled him, and said, Thou art his disciple; but we are disciples of Moses.

This was a false boast on the part of the Pharisees. Jesus himself said that if they had believed Moses, they would have believed Christ. They were not the Israel of God in the spiritual sense (Romans 9:6-8).

Thou art his disciple ... Such an indirect admission (John 9:27) was all they needed; and they at once heaped upon him the full weight of their scorn, invective, and slander. They reviled him. Such was the justice and such was the pity of those sons of the devil who sat on Moses' seat in the times of Christ. What had the blind man done to deserve their hatred and abuse? He had merely recognized in deepest humility and appreciation the mercy extended to him by the Lord. What a shock this encounter with the religious leaders must have been to him!