Firstly, we have some copyists to thank from the inter-testamental period for collapsing YHWH into Kyrios, thanks for that, so now we have, in both old and new testaments “The Lord/LORD says to my Lord”.
YHWH said to my Lord already gives me something to stand on, but I need it for what is next.
We would love to think that David was seeing some kind of super messiah vision and talking directly to Jesus, right? So what is with verse 5? The Lord (not LORD) is at your right hand. Is the first-person-psalm recounter now talking to someone else? Is he in fact now praying to YHWH? Who is the author to inform YHWH about the Lord (lowercase) crushing kings on the day of his wrath?
It’s been clear to many - to me only as mud!