Church Fathers on Luke 17:23

When our Lord said, The kingdom of God is within you, He would fain prepare His disciples for suffering, that being made strong they might be able to enter the kingdom of God; He therefore foretells to them, that before His coming from heaven at the end of the world, persecution will break out upon them. Hence it follows, And he said to the disciples, The days will come, &c. meaning that so terrible will be the persecution, that they would desire to see one of His days, that…

For their life was then without trouble, for Christ took care of them and protected them. But the time was coming when Christ should be taken away, and they should be exposed to perils, being brought before kings and princes, and then they should long for the first time and its tranquillity.

Or, by the day of Christ He signifies His kingdom, which we hope will come, and He lightly says, one day, because there shall no darkness disturb the glory of that blessed time. It is right then to long for the day of Christ, yet from the earnestness of our longing, let us not vision to ourselves as though the day were at hand. Hence it follows, And they shall say to you, Lo here! and, Lo there!