Were filled with madness - Probably,
1. Because he had shown his "power" to work a miracle.
2. Because he had shown his power to do it "contrary" to what "they" thought was right.
3. Because by doing it he had shown that he was from "God," and that "they" were therefore "wrong" in their views of the Sabbath. And,
4. Because he had shown no respect "to their views" of what the law of God demanded.
Pride, obstinacy, malice, and disappointed self-confidence were "all" combined, therefore, in producing madness. Nor were they alone. Men are often enraged because others do good in a way which "they" do not approve of. God gives success to others; and because he has not accommodated himself to "their" views of what is right, and done it in the way which "they" would have prescribed, they are enraged, and filled with envy at people more successful than themselves.
Communed one with another - Spoke together, or laid a plan.

They were filled with madness - Pride, obstinacy, and interest, combined together, are capable of any thing. When men have once framed their conscience according to their passions, madness passes for zeal, the blackest conspiracies for pious designs, and the most horrid attempts for heroic actions. Quesnel.

And they were filed with madness,.... Both at the cure, and because they could not answer him; nor properly fix a charge upon him, or accuse him before the people, without bringing their resentments on them:
and communed one with another what they might do with Jesus: this they did after they came out of the synagogue, and when with the Herodians, as in See Gill on Mark 3:6.

filled with madness--The word denotes senseless rage at the confusion to which our Lord had put them, both by word and deed.
what . . . do to Jesus--not so much whether to get rid of Him, but how to compass it. (See on Matthew 3:6.)