You will see the angels of God ascending and descending ON the Son of Man

[tonychanyt]

John 1:

47 Jesus saw Nathanael coming toward him and said of him, “Behold, an Israelite indeed, in whom there is no deceit!” 48 Nathanael said to him, “How do you know me?” Jesus answered him, “Before Philip called you, when you were under the fig tree, I saw you.” 49 Nathanael answered him, “Rabbi, you are the Son of God! You are the King of Israel!” 50 Jesus answered him, “Because I said to you, ‘I saw you under the fig tree,’ do you believe? You will see greater things than these.” 51 And he said to him, “Truly, truly, I say to you, you will see heaven opened, and the angels of God ascending and descending on the Son of Man.”

on
ἐπὶ (epi)
Preposition
Strong's 1909: On, to, against, on the basis of, at.

Son
Υἱὸν (Huion)
Noun - Accusative Masculine Singular

What does "on the Son of Man" mean?

The Greek expression is ἐπὶ, followed by accusative.

Thayer's Greek Lexicon:

after verbs expressing motion toward a place, to denote a remaining in the place after the motion

Here, we have the motions of angels ascending and descending.

International Standard Version:

Then he told him, "Truly, I tell all of you emphatically, you will see heaven standing open and the angels of God going up and coming down to the Son of Man."

An example of this is in Matthew 3:

16 As soon as Jesus was baptized, he went up out of the water. At that moment heaven was opened, and he saw the Spirit of God descending like a dove and alighting on him.