my_torah

Psalm 87 is a very hard Psalm to understand or translate.

I believe that Rashi has the key to its understanding when he points to a reference back to Isaiah 66 verses 20 to 21.

read against this background it may be better translated not as it is usually construed:
"A Song of the sons of Korach: He has set his foundation on the holy mountain"
but rather:
"A Song for the sons of Korach, based on the "Holy Mountain" passage (in Isaiah):".

It also has a rather nice chiasmic structure:

Isaiah 66: 20 – 21

 

“And they shall bring all your brethren out of all the nations as an offering unto the LORD, on horses, and in chariots, and in litters, and on mules, and on swift beasts, to My holy mountain Jerusalem, says the LORD, just as the children of Israel bring their offering in a clean vessel into the house of the LORD.

And of them also, will I take for Priests and for Levites, says the LORD.”

Psalm 87  
For the Bene-Korach (temple-singers), a song with musical accompaniment, it’s basis being The holy mountains (Jerusalem):

 The Lord loves the gates of Zion, more (even) than all the dwelling-places of Jacob.

You are ascribed (great) honour: “The City of God”     

--(sela)--

I shall remind the Dragon (of Egypt) and Babylon of them that know Me – behold (also) Philistia and Tyre with Kush, (saying) “This one was born there”.

And of Zion it will be said: “This person, and this person, was born in her” and He will establish her (as) the highest.

The Lord will count them when He inscribes the (fate of the) Peoples, (saying of each): “This one was born there”.

--(sela)--

Singers and Musicians: “All my innermost (yearnings) are for you”.

https://ibb.co/W0gS37J