Matthew 24:27

“For as the lightning comes forth from the east, and is seen even to the west, so will be the coming of the Son of man.”

And the reason for that is because when the Son of Man does come it will be as swift and as sudden and as glorious as a flash of lightning. It will be a heavenly, not an earthly, coming.

One of Jesus' temptations had been to put on a spectacular display of power on earth so as to gather a following (Matthew 4:5), a way that He had rejected. And some of these Messiahs may well seek to do something similar. But He wants His followers to know that He will never act in that way. When He speaks of His glorious appearing here He is rather speaking of the inevitable manifestation of His true and heavenly glory which in the end cannot be hidden.

That the expression ‘Son of Man' found here and in the following verses refers to Jesus seen as a heavenly figure, but as also closely related to previous uses of the expression with regard to His life as a human being on earth, is confirmed by the fact that here He is represented as the true Messiah as against false Messiahs, and the true Prophet as against false prophets, for there has been constant emphasis on the fact that Jesus is the outstanding and unique Prophet (Matthew 12:41) and the true Messiah (Matthew 16:16). It is also required by the constant previous references to Jesus as the Son of Man under all conditions.