BTW, what is an ancient sky, and what does it mean to ride one?
Can't tell if that's a sincere question but I'll give it a sincere answer--I'll try to be brief as I could dedicate pages to this topic alone.
I've always assumed the song was a reference to Daniel 7 (some other verses as well); possibly THE most important passage to a Christian.
The "rider of the clouds" title was one of Baal but was also used as a polemic by the Biblical writers. So anyone reading Daniel 7 would've known deity was involved anytime that phrase or a variant was used.
Daniel 7:
"13 “In my vision at night I looked, and there before me was one like a son of man,[a] coming with the clouds of heaven. He approached the Ancient of Days and was led into his presence. 14 He was given authority, glory and sovereign power; all nations and peoples of every language worshiped him. His dominion is an everlasting dominion that will not pass away, and his kingdom is one that will never be destroyed."
So the "son of man" approaches the Ancient of Days (Yahweh), meaning the two aren't the same, yet this "son of man" is given the title of deity!
It's scenes like this one (and there are others) that caused the Jews, especially during the inter-testimental period, to speculate over the idea of a 2nd Yahweh. This idea was not deemed heretical until 2nd-3rd century AD.
With this in mind, when Jesus was arrested for blasphemy and the high priest asks him if he is the Messiah, Jesus answers by quoting Dan 7.
And they respond with: “He has spoken blasphemy! Why do we need any more witnesses? Look, now you have heard the blasphemy."
It was viewed as blasphemy because Jesus was identifying himself as the cloud rider, which by extension meant he was calling himself God.