'Sign' in the Bible

Then some of the scribes and Pharisees told Jesus, "Teacher, we want to see a sign from you."

But he replied to them, "An evil and adulterous generation craves a sign. Yet no sign will be given to it except the sign of the prophet Jonah,

When the Pharisees and Sadducees arrived, in order to test Jesus they asked him to show them a sign from heaven.

You know how to interpret the appearance of the sky, yet you can't interpret the signs of the times? An evil and adulterous generation craves a sign, but no sign will be given to it except the sign of Jonah." Then he left them and went away.

While Jesus was sitting on the Mount of Olives, the disciples came to him privately and said, "Tell us, when will these things take place, and what will be the sign of your coming and of the end of the age?"

Then the sign of the Son of Man will appear in the sky, and all "the tribes of the land will mourn' when they see "the Son of Man coming on the clouds of heaven' with power and great glory.