A sign from heaven. The Pharisees and Sadducees formed the two main sects of Israel. They did not see eye to eye, for there was much disagreement in their doctrines. But in order to have something against the Lord Jesus, they got together to tempt Him.

They had seen the various miracles that the Master performed, but this was not enough for them because of their unbelief.

So, They maliciously asked Him for a sign form heaven. It seems that they wanted Jesus to make fire come down from heaven or change its appearance with thunder, lightning, and darkness. At that moment, the devil wanted to expose the Son of God.