Mark 8:12
“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.”
And straightway he entered into a ship with his disciples, and came into the parts of Dalmanutha.
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.
And he left them, and entering into the ship again departed to the other side.
Now the disciples had forgotten to take bread, neither had they in the ship with them more than one loaf.
Why This Verse Was Tagged
This verse was identified by multiple independent signals: structural patterns, prophetic context, and vocabulary — then validated by a probability model (Snorkel).
Counter-Arguments
The strongest case that this verse does not belong in this theme.

Cross-References
“But he answered and said unto them, An evil and adulterous generation seeketh after a sign; and there shall no sign be given to it, but the sign of the prophet Jonas:”
“A wicked and adulterous generation seeketh after a sign; and there shall no sign be given unto it, but the sign of the prophet Jonas. And he left them, and departed.”
“And when the people were gathered thick together, he began to say, This is an evil generation: they seek a sign; and there shall no sign be given it, but the sign of Jonas the prophet.”
“But though he had done so many miracles before them, yet they believed not on him:”
“And looking up to heaven, he sighed, and saith unto him, Ephphatha, that is, Be opened.”