Then the Pharisees and Sadducees came, and testing Him asked that He would show them a sign from heaven.
He answered and said to them, "When it is evening you say, 'It will be fair weather, for the sky is red';
"and in the morning, 'It will be foul weather today, for the sky is red and
threatening.' Hypocrites! You know how to discern the face of the sky, but you
cannot discern the signs of the times.
"A wicked and adulterous generation seeks after a sign, and no sign shall be
given to it except the sign of the prophet Jonah." And He left them and departed.
Mark 8:10-12
10 immediately got into the boat with His disciples, and came to the region of
Dalmanutha.11 Then the Pharisees came out and began to dispute with Him, seeking from Him a
sign from heaven, testing Him.12 But He sighed deeply in His spirit, and said, "Why does this generation seek a sign? Assuredly, I say to you, no sign shall
be given to this generation."