Jesus excoriated the Pharisees and Sadducees in Mat 16:1-4 for interpretive blindness. They were asking, yet again, for a sign from heaven while they remained oblivious to the signs of their times. The mirror of the law in front of their faces would have revealed their generational adultery if they only had eyes to see. Jesus had already declared the red and threatening sky of judgement justly hanging over the heads of these blind guides in Mat 12.