Mark 8:11-13 NIV

11 The Pharisees came and began to question Jesus. To test him, they asked him for a sign from heaven.

References for Mark 8:11

12 He sighed deeply and said, “Why does this generation ask for a sign? Truly I tell you, no sign will be given to it.”

References for Mark 8:12

13 Then he left them, got back into the boat and crossed to the other side.