John 9:33

If this man were not of God
If he had not his mission, commission, and credentials from God; if he had not been sent by him, and had not authority from him, and was not assisted by him, as man, or God was not with him,

he could do nothing;
or "not do these things", as the Syriac version reads; that is, such miraculous works; or, as the Persic version, "he could not do this miracle": open the eyes of a man born blind. His doing this is a full proof that he is of God, and comes from him.