Some have passed the point of no return. What they fail to understand is where their journey will end.
1 The Pharisees and Sadducees came to Jesus and tested him by asking him to show them a sign from heaven.
2 He replied, When evening comes, you say, It will be fair weather, for the sky is red, 3 and in the morning, Today it will be stormy, for the sky is red and overcast. You know how to interpret the appearance of the sky, but you cannot interpret the signs of the times. 4 A wicked and adulterous generation looks for a sign, but none will be given it except the sign of Jonah. Jesus then left them and went away.
You may think at first that the fresh appearance of the Sadducees in Galilee means that some new faces are in town (verse 1). The NIVs wording conceals the fact that the whole purpose for the Pharisees and Sadducees approaching Jesus was to test him. We have examined this verbal form before: Greek peirazo can mean either tempt or test, and the hostile context here tells you what is going on. Indeed, this verb occurs only six times in Matthews Gospel, and the first two involve Satan tempting Jesus, while the last four involve emissaries of Satan, as seen here.
Even without such analysis, their request for a sign from heaven rings hollow after Jesus has performed hundreds, perhaps thousands, of miraculous healings in Galilee and the nearby regions. Accordingly, Jesus answers them in a metaphorical way. There is irony here as well, because Jesus will play with the various meanings of heaven as either the place where God dwells or the sphere in which weather occurs. The NIV translates the same Greek noun ouranos as heaven in verse 1 (in the demand from the Pharisees and Sadducees) and sky in verses 2-3 (in the pointed answer that Jesus gives using the weather analogy).
Jesus notes that the religious leaders are experts at reading the signs provided in the ouranos by the changing weather, yet they cannot discern the signs of the favorable moment, the moment of opportunity (verse 3). We know why this is the favorable moment, but the willful blindness of the religious leaders leaves them clueless.
In verse 4, Jesus tersely rejects the request for a sign, but not without calling them a wicked and adulterous generation (verse 4), where the adultery is spiritual and consists of failing to honor their covenant with God. The sign of Jonah is not explained here, but can be found in Matthew 12:40-41. Osborne rightly points out that the sign consists of the resurrection of Jesus and the repentance of Ninevah. The Sadducees did not accept any kind of resurrection, and none of the Jewish religious leaders saw any need to repent. But they could not have been more wrong!
When Jesus left the leaders and Galilee behind, he did not return to Galilee until after his resurrection. Constant opposition put an end to their hour of opportunity.
Copyright 2017 by Barry Applewhite, Plano, Texas. All rights reserved worldwide. Materials originally developed for Christ Fellowship, McKinney, Texas. Used by permission.
 Daniel B. Wallace, Greek Grammar Beyond the Basics (Grand Rapids: Zondervan, 1996), 636.
 Grant R. Osborne, Matthew, Exegetical Commentary on the New Testament (Grand Rapids: Zondervan, 2010), 613.