But when the Pharisees heard it - It was necessary for the Pharisees, who had determined to reject Jesus of Nazareth, to account in "some" way for the miracles he had performed.
Here was a manifest miracle, an exertion of power unquestionably superior to what people could put forth. The common people were fast drawing the proper inference from it, and coming into the belief that this was the Messiah. The authority and power of the Pharisees were declining. Unless, therefore, some way should be devised of accounting for these facts, their influence would be at an end. Whatever way of accounting for them was adopted, it was necessary that they should acknowledge that there was "superhuman power." The people were fully persuaded of this, and no man could deny it. They therefore ascribed it to the prince of the devils - to Beelzebub. In this they had two objects:
1. To concede to the people that here was a "miracle," or a work above mere human power.
2. To throw all possible contempt on Jesus. Beelzebub, or Beelzebul, as it is in the Greek, and correctly rendered in the margin, was an opprobrious name given to the leader of the devils as an expression of supreme contempt. See the notes at Matthew 10:25.

Beelzebub - See Matthew 10:25.

But when the Pharisees heard it,.... Very probably not the same that went out, and held a council against Christ to destroy him, Matthew 12:14 but others that were come from Judea and Jerusalem, and were with him in the house, and saw the miracle: these, when they heard what the people said, and how ready they were to believe, and own Jesus to be the Messiah, in order to prevent it, being filled with envy and malice,
they said, this fellow doth not cast out devils but by Beelzebub, the prince of devils. They could not deny the miracle, or that it was one; but to deprive him of the glory of it, and even reproach him for it, and to bring him into contempt with the people, they not only speak of him in a scornful manner, "this" sorry man, "this" vile fellow; but ascribe the miracle he wrought to familiarity with the devil, to diabolical influence and skill in magic art: they pretended he was in confederacy with Satan, and was carrying on his interest: and therefore, that he might gain credit and reputation, the prince of devils suffered the inferior ones to remove at his word: and of these their ancestors, the Jews have learnt to fix this vile imputation, and blasphemous piece of slander upon Christ; who, they say (o), brought enchantments, or witchcrafts, out of Egypt, in the cuttings of his flesh, whereby he performed the things he did. Concerning Beelzebub; see Gill on Matthew 10:25 here called "the prince of devils"; it being a prevailing notion among the Jews, that there is one devil who is the head of all the rest, and who is by them sometimes called Asmodeus: they say (p), when Solomon sinned against the Lord, he sent to him , "Asmodeus the king of the devils", and drove him from his throne, and so elsewhere (q): and sometimes Samael, who is styled (r) Samael the prince, , "the king of devils"; and the angel Samael, the wicked, , "the head of all the Satans", or devils (s): and we often read (t) of , "the prince of hell"; by whom the same is meant, as here, by Beelzebub; for if anyone devil is more wicked, odious, and execrable than the rest, the chief of them may be thought to be so; for which reason he is here mentioned.
(o) T. Hieros. Sabbat, fol. 13. 4. T. Bab. Sabbat, fol. 104. 2. (p) Targum in Eccl. i. 12. (q) T. Bab. Pesach, fol. 110. 1. Gittin, fol. 68. 1. & Raziel, fol. 41. 2. (r) Zohar in Deut. fol. 120. 3. (s) Debarim Rabba, fol. 245. 3. (t) T. Bab. Sanhedrim, fol. 52. 1. Imre Binah in Zohar in Genesis. fol. 22. 3.

But when the Pharisees heard it--Mark (Mark 3:22) says, "the scribes which came down from Jerusalem"; so that this had been a hostile party of the ecclesiastics, who had come all the way from Jerusalem to collect materials for a charge against Him. (See on Matthew 12:14).
they said, This fellow--an expression of contempt.
doth not cast out devils, but by Beelzebub--rather, "Beelzebul" (see on Matthew 10:25).
the prince of the devils--Two things are here implied--first, that the bitterest enemies of our Lord were unable to deny the reality of His miracles; and next, that they believed in an organized internal kingdom of evil, under one chief. This belief would be of small consequence, had not our Lord set His seal to it; but this He immediately does. Stung by the unsophisticated testimony of "all the people," they had no way of holding out against His claims but the desperate shift of ascribing His miracles to Satan.

The Pharisees hearing it. Compare Mark 3:22-27. Mark says that some of these Pharisees were scribes who had come from Jerusalem. The ecclesiastical authorities at Jerusalem were now keeping their watch on Jesus.
He casteth not out devils but by Beelzebub. See note on Matthew 10:25. Beelzebub, the prince of devils, meant the same as Satan. The Pharisees assert that the Lord's miraculous power is due to the aid of the devil.

Mark 3:22.