“As the lightning

Flashes

And lights up

The sky

From one side

To the other,

So will the Son of man

Be in his day.”

ὥσπερ γὰρ ἡ ἀστραπὴ ἀστράπτουσα ἐκ τῆς ὑπὸ τὸν οὐρανὸν εἰς τὴν ὑπ’ οὐρανὸν λάμπει, οὕτως ἔσται ὁ Υἱὸς τοῦ ἀνθρώπου ἐν τῇ ἡμέρᾳ αὐτοῦ.

Luke indicated that Jesus said that as the lightning flashes (ὥσπερ γὰρ ἡ ἀστραπὴ ἀστράπτουσα) and lights up the sky (ἐκ τῆς ὑπὸ τὸν οὐρανὸν) from one side of the sky to the other (εἰς τὴν ὑπ’ οὐρανὸν λάμπει), so will the Son of man be (οὕτως ἔσται ὁ Υἱὸς τοῦ ἀνθρώπου) in his day (ἐν τῇ ἡμέρᾳ αὐτοῦ).  Luke was the only Greek biblical writer to use the word ἀστράπτουσα that means to lighten and flash forth.  There was something similar in Matthew, chapter 24:27, indicating a Q source, about the Son of Man coming like lightening, but in a more succinct way.  In Matthew, Jesus said that as the lightning came from the east (ὥσπερ γὰρ ἡ ἀστραπὴ ἐξέρχεται ἀπὸ ἀνατολῶν) but flashed or shined in the west (καὶ φαίνεται ἕως δυσμῶν), so the Parousia or the second coming of the Son of Man would happen (οὕτως ἔσται ἡ παρουσία τοῦ Υἱοῦ τοῦ ἀνθρώπου).  Wherever the corpse was (ὅπου ἐὰν ᾖ τὸ πτῶμα), there the vultures gathered (ἐκεῖ συναχθήσονται οἱ ἀετοί).  The Son of Man was a clear reference to Jesus in his return, the Parousia, who would return like a flash of lightening.  The vultures or eagles were a reference to the Roman soldiers with their eagle symbols.  There was nothing about the corpses and the eagles or vultures here in Luke, just the lightning flash.  However, later in this chapter, verse 37, there was a mention of the corpses and these vultures.  Are you afraid of lightning?