Mark 8:11

Matthew noted that the Sadducees accompanied the Pharisees (Matthew 15:1). They came out from Jerusalem again to argue, not to learn. They asked Jesus to provide some confirmation of His divine authority and trustworthiness. They wanted an immediate, public, definitive proof that God was with Him (cf. Mark 11:30). They had previously concluded that His power came from Satan (Mark 3:22). The miracles that Jesus performed did not convince them. They were not requesting another one of these but a different type of verification, perhaps similar to those God gave the Israelites at Mt. Sinai to authenticate Moses as His servant. They did this to subject Jesus to a trial (Gr. peirazo) that would reveal His true character. They hoped to expose Him as a phony.

"’Sign’ (semeion) consistently differs in Mark from ’wonders’ or ’miracles’ (dunameis). Nowhere in the Synoptics does ’sign’ refer to a ’miracle’ or is a miraculous event called a ’sign.’ . . . They sought a ’sign’ in the OT Jewish sense, a confirmation or authentication of Jesus’ ministry." [Note: Guelich, p. 413.]

Probably the Pharisees wanted Jesus to give them indisputable proof that God confirmed Jesus’ credibility. [Note: Ibid., p. 414.]

"The Pharisees were progressive, a party among, though not of, the people. Their goal was that Israel should become the righteous nation of the covenant. To this end they taught compliance with the ’tradition of the elders,’ an oral code of conduct effectively adapting the law of Moses to later times and changing demands." [Note: Kingsbury, pp. 63-64.]