(20) He hath a devil, and is mad.--Comp. Note on John 8:48. The words "and is mad" are explanatory of the possession by a demon.

10:19-21 Satan ruins many, by putting them out of conceit with the word and ordinances. Men would not be laughed out of their necessary food, yet suffer themselves thus to be laughed out of what is far more necessary. If our zeal and earnestness in the cause of Christ, especially in the blessed work of bringing his sheep into his fold, bring upon us evil names, let us not heed it, but remember our Master was thus reproached before us.And many of them said, he hath a devil, and is mad,.... It was a notion of the Jews, that madness or distraction was from the devil, and therefore these two are here joined together, having a devil, and being mad: there is a spirit which they call Tazazith, and which, they say (z), is an evil spirit that takes away the understanding of men; and under the influence of such a "demon", the Jews thought Christ to be: and therefore say,

why hear ye him? he is a lunatic, he is distracted, he is a madman; how can you bear to hear such ranting blasphemous stuff, which no man in his, senses would ever utter? nor is anything he says to be regarded, since he is not in his right mind; but is under the power and influence of some evil spirit, which instills these wild and frantic notions into him, and puts him upon venting them; but surely no sober man will ever heed to them.

(z) R. David Kimchi, Sepher Shorash rad.