Mark 8:12 in the World English Bible
He sighed deeply in his spirit and said, “Why does this generation seek a sign? Most certainly I tell you, no sign will be given to this generation.”
Context
11 And the Pharisees came forth, and began to question with him, seeking of him a sign from heaven, tempting him.
12 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.
13 And he left them, and entering into the ship again departed to the other side.