So the Temple was the one significant symbol of the Lordship of their God, of their hope of deliverance from the domination of Rome. To announce the ruin of the Temple was to say that Israel would cease being the people of God. And since they could not conceive of their God existing without His people to worship Him, this was to them blasphemy. Many troubles and sufferings will be the birth-pangs of the new order, Jesus replied. The time is near.
Summer comes soon after the fig-tree begins to sprout.
The time is unknown. Constant vigilance and preparedness is the only way to prepare for His coming. They were alert both to the present and the future. I'm not so sure the Second Coming of Christ is so far off at all. The sands of the age are falling ever more swiftly into the hourglass.