Matthew Poole and continuators on Luke 17:24

24 For as the lightening that lighteneth out of the one part under heaven, shineth unto the other part under heaven: so shall also the Son of man be in his day.

See the Notes on Matth 24.23, 27. You will (saith our Saviour) have a great many false Christs, and false Prophets arise, and foolish credulous People will be deceived by them, and come and tell you, Lo yonder is the Messiah, or Lo he is in another place, but believe them not. So it is in Mark 13.21. follow them not, saith Luke. The Son of Man shall have his Day, a Day when he will come in a Glorious manner to Judge the Quick, and the Dead; but it will come upon the World like Lightning, that suddenly shineth from one part of Heaven to another, so as no Man can foretel it, or observe the Motion of it. Some do think that by the Day of the Son of Man, here was meant the spreading of his Gospel, but certainly, it is a strained sense, nor was the spreading of that a thing so sudden, but more gradually, and observably accomplished.