John 6:30

And it shall come to pass, if they will not believe thee, neither hearken to the voice of the first sign, that they will believe the voice of the latter sign.

And he gave a sign the same day, saying, This is the sign which the LORD hath spoken; Behold, the altar shall be rent, and the ashes that are upon it shall be poured out.

Ask thee a sign of the LORD thy God; ask it either in the depth, or in the height above. But Ahaz said, I will not ask, neither will I tempt the LORD. And he said, Hear ye now, O house of David; Is it a small thing for you to weary men, but will ye weary my God also? Therefore the Lord himself shall give you a sign; Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel.

Then certain of the scribes and of the Pharisees answered, saying, Master, we would see a sign from thee.

The Pharisees also with the Sadducees came, and tempting desired him that he would shew them a sign from heaven. He answered and said unto them, When it is evening, ye say, It will be fair weather: for the sky is red. And in the morning, It will be foul weather to day: for the sky is red and lowering. O ye hypocrites, ye can discern the face of the sky; but can ye not discern the signs of the times? 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.

Then answered the Jews and said unto him, What sign shewest thou unto us, seeing that thou doest these things?

(For his disciples were gone away unto the city to buy meat.)