Mark 8:10

So they did eat, and were filled: and they took up of the broken meat that was left seven baskets.

And they that had eaten were about four thousand: and he sent them away.

And the Pharisees came forth, and began to question with him, seeking of him a sign from heaven, tempting him.

And he sighed deeply in his spirit, and saith, Why doth this generation seek after a sign? verily I say unto you, There shall no sign be given unto this generation.