What does John 10:19-21 mean?

19 There was a division therefore again among the Jews for these sayings. 20 And many of them said, He hath a devil, and is mad; why hear ye him? 21 Others said, These are not the words of him that hath a devil. Can a devil open the eyes of the blind? (John 10:19-21 KJV)

William Burkitt’s Commentary

Here the evangelist shews what different effects this sermon of our Saviour had upon the Jews; many of them calumniate and slander him, as one possessed and mad, and therefore not to be heard and minded; others of calmer thoughts said, That the doctrine be taught, and the late miracle which he had wrought in curing the blind man, were abundantly sufficient to confute such a groundless slander.

Learn hence, That the doctrine of Christ meeting with diversity of dispositions, it is no wonder that it occasions different effects, to the softening of some, and hardening of others: even as the same sun that melteth the wax, hardeneth the clay; yet is not this to be imputed to the doctrine of our Saviour, but to men’s corruptions which oppose the truth, and the maintainers of it. There was a division again amongst them.