Jamieson, Fausset and Brown on Matthew 12:27

27. And if I by Beelzebub cast out devils, by whom do your children--"your sons," meaning here the "disciples" or pupils of the Pharisees, who were so termed after the familiar language of the Old Testament in speaking of the sons of the prophets (1Ki 20:35; 2Ki 2:3, &c.). Our Lord here seems to admit that such works were wrought by them; in which case the Pharisees stood self-condemned, as expressed in Luke (Lu 11:19), "Therefore shall they be your judges."