by jimwalton » Mon Jan 29, 2018 5:40 pm
Let's go through the text. They ask for a sign. The word is *semeion*, and it often designates a miracle. More likely, though, most ancient people, including the Jews in this era, believed that signs in the heavens predicted events about to take place, but more importantly that if someone claimed authority in teaching and prophecy it would often be accompanied by some sign to authenticate the divine message (sort of like Moses being able to make his stick turn into a serpent, or Elijah having Gehazi's eyes opened to see the armies of God protecting the city). We see examples of this kind of thing in 1 Sam. 1 Sam. 2.30-34; 1 Ki. 20.1ff; Isa. 7.10ff. The Jewish apocalypse did speak of spectacular displays of power by the Messiah, "The Son of Man." The devil had suggested that Jesus let the people see him drop down from the pinnacle of the temple and not get hurt.
So they want a sign. Do they want fire from heaven? Some kind of miracle or trick to prove Jesus's identity and message? As opposed to the earthly kinds of miracles Jesus is already doing, they obviously want something more, something different.
But the text specifically says they weren't sincere, they were just testing him (as the Israelites tested God in Ex. 17.1-7). We can assume their intent was negative. In requesting a sign, they want a public, definitive proof that God is with him. They are trying to "test the prophet" according to Dt. 13.2-6; 18.18-22. They want a prophecy that will definitively come true in short order. Their question is tantamount to "What is the source of your authority?" (Remember that previously they accused that his authority was Satanic.)
Jesus responds to them in Matthew 16.2-3: You clearly know how to read obvious signs ("Red sky at night, sailors' delight"). But then why can't you see the obvious about me?
Then in Matthew 16.4 he says they won't get a sign, "except the sign of Jonah." The sign of Jonah was Jesus's death and resurrection, still quite future. It wasn't what they were asking for, but it was exactly the "pièce de résistance" they were demanding. There would be no lightning from the sky or turning the water to blood, and Jesus wouldn't conform to their request for a trick-on-demand. His death and resurrection would indeed be a confirmation of his identity and his work, and at the same time a condemnation of their apostasy and unbelief (Mt. 21.18-20—the illustration of the fig tree, the authority of Jesus questioned [vv. 23-27], the parable of the two sons [vv.28-32], and the parable of the tenants [vv. 33-46]).
"The sign of Jonah" was an analogy of dying and rising and a warning about hearing and disobeying. It's not really a sign at all, not as they were asking for. It was a declaration about his resurrection, a prediction that they would not believe, and a warning that only judgment would ensue.