Tehillim 110 - Hashem's place in it

Question

In Psalm 110, posuk 1, there are two subjects spoken about -- the 4-letter name of Hashem (ad-o-niy) and the master (either David or Avraham depending on which of the commentators one accepts). But in posuk 5 the text reads:

אֲדֹנָ֥י עַל־יְמִֽינְךָ֑ מָחַ֖ץ בְּיוֹם־אַפּ֣וֹ מְלָכִֽים׃

The translations I see view this as a statement that Hashem is on the right hand of someone ("The Lord is at your right hand" from Sefaria and "The Lord, on your right hand," from Chabad). This brings up 2 questions:

On whose right hand is Hashem? The opening posuk has Hashem speak to the "master" telling him to sit at Hashem's right hand. This would put Hashem at the LEFT hand of that person. The answer I have seen is that this is not talking about the same scene - but is a reference to a separate battle scene when Hashem is at the the right hand (metaphorically) of David (or, I guess, Avraham). Is that the prevailing explanation?

But then why, in posuk 5, is Hashem referred to by the actual spelling of the word a-d-n-y and not the 4 letter name (which distinguished him from the master in posuk 1) which we would pronounce Ad-o-niy?

Answer 1

In the Artscroll Tanach Series on Tehillim Vol. 2 (Mesorah Publications - p.1343) it writes the following commentary on posuk 5:

אֲדֹנָ֥י עַל־יְמִֽינְךָ֑ - My Lord is at your right

Previously (verse 1), Abraham is described as sitting at G-d's right hand, with G-d therefore, at Abraham's left. Now the Psalmist places G-d at Abraham's right hand. This alludes to the statement in the Yalkut Shimoni, that, in the future, G-d will place the Messiah at His right hand and Abraham at His left. Abraham will protest, "Why is the Messiah, my descendant, privileged to sit, at Your right hand, while I sit at Your left?" Then G-d will appease Abraham, saying, "Your descendant sits at My right hand, but I sit at your right hand."