Pharisees Demand a Miraculous Sign
11 When the Pharisees heard that Jesus had arrived, they came and started to argue with him. Testing him, they demanded that he show them a miraculous sign from heaven to prove his authority.
12 When he heard this, he sighed deeply in his spirit and said, "Why do these people keep demanding a miraculous sign? I tell you the truth, I will not give this generation any such sign." 13 So he got back into the boat and left them, and he crossed to the other side of the lake.
Yeast of the Pharisees and Herod
14 But the disciples had forgotten to bring any food. They had only one loaf of bread with them in the boat. 15 As they were crossing the lake, Jesus warned them, "Watch out! Beware of the yeast of the Pharisees and of Herod."
16 At this they began to argue with each other because they hadn't brought any bread. 17 Jesus knew what they were saying, so he said, "Why are you arguing about having no bread? Don't you know or understand even yet? Are your hearts too hard to take it in? 18 You have eyes - can't you see? You have ears - can't you hear?' Don't you remember anything at all? 19 When I fed the 5,000 with five loaves of bread, how many baskets of leftovers did you pick up afterward?"
"Twelve," they said.
20 "And when I fed the 4,000 with seven loaves, how many large baskets of leftovers did you pick up?"
"Seven," they said.
21 "Don't you understand yet?" he asked them.
Following the miraculous feeding of the mostly Gentile crowd, Jesus is confronted by a group of Pharisees demanding he produce for them "a miraculous sign from heaven" to verify his authority. Jesus refuses to give them any such sign, and he departs with his disciples. They, in turn, show a similar lack of recognition regarding Jesus' true identity.
A miraculous sign (Mark 8:11)
"The rabbis were splitting hairs over the miracles of Jesus as having a possible natural explanation (as some critics do today) even if by the power of Beelzebub, and those not of the sky (from heaven) which would be manifested from God. So they put up this fantastic test to Jesus which he deeply resents."626 In demanding a miraculous sign from Jesus, the Pharisees were seeking "unmistakable proof that He and His mission were authorized by God"627 - perhaps something on par with the miracles performed by Moses during the Exodus.628 (While Jesus had miraculously multiplied earthly bread on two different occasions, Moses [actually, God] had provided bread from heaven [manna] on a daily basis for 40 years. [see John 6:30-35]629 But of course such reasoning completely ignores the fact that, as God incarnate, Jesus was/is greater than Moses, manna, and all the Bible's miracles combined.) "The reasoning seems to be that, since the Messiah will be greater than all the prophets and even than Moses, he will prove it by doing at least one sign which in outward grandeur will exceed all other signs that have ever been wrought."630 (Of course, Jesus' resurrection was/is such a sign [see Matthew 16:4] - but only for those willing to believe.)
I will not give ... any such sign (Mark 8:12)
Why did Jesus refuse to grant the religious leaders' request for a sign? Because there had already been signs aplenty for anyone willing to see: the handicapped had been restored; the sick had been healed; lepers had been cleansed; waves had been stilled; the hungry had been fed; and the dead had been raised back to life.631 Moreover, the religious leaders' demand actually represented a temptation.632 Like Satan in the wilderness at the beginning of Jesus' ministry, the Pharisees wanted Jesus to provide a miracle or wonder633 that would convince them he was sent from God.
Several points are worth noting:
Authority. The Pharisees already knew that Jesus could perform the supernatural; they wanted Jesus to prove to their satisfaction that his miracles and wonders were from God.634 Just as the apostle Paul signed his letters as a way of guaranteeing their authenticity (see 2 Thessalonians 3:17), the religious leaders demanded to see God's signature, so to speak, as a guarantee of Jesus' ministry.635 If Jesus had given in to their demand, he would in effect have been declaring that the Pharisees' self-appointed (= illegitimate) authority was greater than his God-given (= legitimate) authority. "The frustrated Pharisees tried a tactical maneuver with Jesus called 'control by demanding proof.' ... If they could raise doubts and thus get Jesus to do miracles at their command, then he would literally be under their control. ... They had already seen and heard about many miracles, but that was not enough for them. They wanted Jesus to answer to them."636
Insincerity. The Pharisees were not sincere. "They had already decided not to believe. Hearts can become so hard that even the most convincing facts and demonstrations will not change them."637 Their true intent "was to embarrass Jesus, either because God would not perform the requested sign, or that the sign itself would fail to impress and persuade."638 Hence their aim was to "discredit [Jesus] completely with the people."639
Skepticism. No miracle can convince a die-hard skeptic. "Unbelief can be a mind-set against God, a willful rebellion of the intellect such that no amount of evidence will overcome it."640 While Jesus always welcomed sincere seekers, the Pharisees had already proved themselves to be hardcore skeptics of Jesus by charging that his many marvelous miracles were not from God (see Mark 3:20-30).641 Although a miraculous sign may serve as "a guarantee of the authenticity of the Sent One and of the truth of the teaching, it has demonstrative power only for souls that are well-disposed or believing. It can provoke astonishment or emotion, even admiration (John 2:23; 6:26; Acts 8:9, 13) without adherence: 'Even though he had done so many signs in their presence, still they did not believe in him' (John 12:37)."642 As one source puts it: "An appeal for a miracle can be a legitimate expression of one's faith (e.g., Mark 5:23; 7:26, 32). But such an appeal is illegitimate if it arises out of unbelief, as was true of the Pharisees."643
Resurrection. At his resurrection from the dead, Jesus would be "declared the Son of God with power" (Romans 1:4, NASB). But even that incredible miracle would not be enough for anyone adamantly refusing to believe. Here we might note Matthew's fuller version of this episode, in which Jesus declared: "'Only an evil, adulterous generation would demand a miraculous sign, but the only sign I will give them is the sign of the prophet Jonah'" (Matthew 16:4, NLT).
Yeast (Mark 8:15)
What did Jesus mean by "the yeast [/leaven] of the Pharisees and of Herod"? Jesus lumped together two opposing factions - "the very strict Pharisees" and the "pro-Roman Herodian dynasty" - in an apparent warning against any popular but dangerous movement that "oppose[s] Jesus' ministry."644 When we factor in the Sadducees that are mentioned in Matthew's account, it is possible to see a warning against: traditionalism (Pharisees); secularism (Herod and the Herodians [= influential Jewish supporters of Herod who worked to keep his dynasty in power645); and skepticism (Sadducees).646 No matter how fashionable it may be, any movement that openly opposes Jesus has the dire potential to lead many people astray.647 When presented with clear and compelling evidence that Jesus was the promised Messiah of God, the religious and political leaders chose to reject him. In turn, their "heart-heartedness ... permeate[d] and contaminate[d] the entire society and [made] it rise up against Jesus."648
"Leaven is used in making bread. It passes secretly, silently, but certainly through the mass of dough."649 Yeast, or leaven, is used most often in the NT "metaphorically of inveterate [= 'firmly established by long persistence'650] mental and moral corruption, viewed in its tendency to infect others."651 In that respect the "yeast" represents unbelief as evidenced by the religious leaders' demand for a spectacular sign (the Pharisees refused to believe Jesus; Herod had refused to believe John the Baptist).652 And so Jesus "is appealing to [his disciples] to understand that the authority he possesses cannot be proved by a sign. Only by faith [/belief] can they recognize him as the bringer of God's salvation."653 We should also understand "yeast" in the sense of "evil teaching, considered as a very powerful, increasingly corrupting influence"654 (see Matthew 16:12).655 The religious leaders were not content to keep their unbelief to themselves; they worked it into the lives of others in the form of false teaching. Not even committed followers of Jesus are immune to this yeast - hence Jesus' warning to be on guard against it.656
The disciples thought that Jesus was rebuking them for not bringing along enough food to eat. And so Jesus reminded them of the two miraculous feedings in which he had not only met the need of thousands but also provided extra for his disciples in the form of leftovers. "[T]he point of this remembrance is not that so many were miraculously filled, but that the disciples themselves received plenty."657 Jesus' gentle scolding was a memorable way of reminding his disciples that he was the divine Son of God who could/would meet all their needs, whether physical or spiritual.658
Giving It All Away
The story is told of a man who was lost in the desert. Dying of thirst, he came across an old shack inside of which was an old, rusty water pump. He immediately grabbed the handle and vigorously pumped up and down, up and down. But there was no water.
That's when he noticed an old jug off to the side on which was written a note instructing the reader to prime the pump with all the water in the jug, and then be sure to refill the jug before leaving.
For a moment the man was utterly confused. Should he believe the note and pour out all the water? Or should he drink all the water from the jug and then move on?
In an act of faith, he decided to follow the instructions. He poured all the water into the old, rusty pump and once again began pumping the handle up and down. At first nothing happened. But then, before he knew it, fresh, cool, life-giving water was gushing from the pump!
He drank until he could not hold another drop. Then he refilled the jug and added a little note of his own: "Believe me, it really works. You have to give it all away before you can get anything back."659
As God's never-ending supply of life-giving water, Jesus calls everyone everywhere to come and have their spiritual thirst satisfied in him (see John 4:5-14). There is, however, one condition: we must first empty ourselves of all our stubborn pride and arrogance before we can humbly receive this life-giving water. This is something the Pharisees refused to do. But it is something that must be done - not one time only, but on a daily basis.
??? What can this passage teach us about what it takes to see Jesus for who he really is?