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 as he sat upon the mount of Olives, the disciples came unto him privately, saying, Tell us, when shall these things be? and what shall be the sign of thy coming, and of the end of the world?
… 
30 And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory.
Tell us, when shall these things be? and what shall be the sign when all these things shall be fulfilled?
12 And this shall be a sign unto you; Ye shall find the babe wrapped in swaddling clothes, lying in a manger.
29 ¶ 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.
And they asked him, saying, Master, but when shall these things be? and what sign will there be when these things shall come to pass?