Church Fathers on Matthew 12:25

The Pharisees ascribed the works of God to the Prince of the daemons; and the Lord makes answer not to what they said, but to what they thought, that even thus they might be compelled to believe His power, Who saw the secrets of the heart; 'Jesus, knowing their thoughts, said unto them.'

Above they had accused Christ of having cast out daemons by Beelzebub; but then He did not reprove them, suffering them, if they would, to acknowledge Him from further miracles, and to learn His greatness from His doctrine. But because they continued to maintain the same things, He now rebukes them, although their accusation had been very unreasonable.

For a city or family is analogous to a kingdom; as it follows, 'And every city or house divided against itself shall not stand.'