Matthew 12:36

“Either make the tree good and its fruit good, or make the tree corrupt and its fruit corrupt; for the tree is known by its fruit.

You offspring of vipers, how can you, being evil, speak good things? For out of the abundance of the heart, the mouth speaks.

The good man out of his good treasure brings out good things, and the evil man out of his evil treasure brings out evil things.

For by your words you will be justified, and by your words you will be condemned.”

Then certain of the scribes and Pharisees answered, “Teacher, we want to see a sign from you.”

But he answered them, “An evil and adulterous generation seeks after a sign, but no sign will be given to it but the sign of Jonah the prophet.