'Sign' in the Bible

Then some of the scribes and Pharisees answered him saying, "Teacher, we want to see a sign from you!"

But he answered [and] said to them, "An evil and adulterous generation desires a sign, and no sign will be given to it except the sign of the prophet Jonah!

And [when] the Pharisees and Sadducees came to test [him], they asked him to show them a sign from heaven.

An evil and adulterous generation seeks for a sign, and a sign will not be given to it except the sign of Jonah!" And he left them [and] went away.

And [as] he was sitting on the Mount of Olives, the disciples came up to him privately, saying, "Tell us, when will these [things] happen, and what [will be] the sign of your coming and of the end of the age?"

And then the sign of the Son of Man will appear in heaven, and then all the tribes of the earth will mourn, and they will see the Son of Man arriving on the clouds of heaven with power and great glory.

Now the one who was betraying him had given them a sign, saying, "[The one] whom I kiss--he is [the one]. Arrest him!"