Can some explain PSALM 137 New Revised Standard Version of the Bible?

I do not have the RSV but the Psalm is a lament over the captivity of the Israelites by the Babylonians and a prophecy of the destruction of Babylon by the Medes and the Persians. It describes how they will treat the Babylonians.

Yes, it came true. God even named the king who would lead the Medo-Persian forces and the manner by which he would attack the city.

A person can better know the true meanings of stories from the Bible if he or she meditates on them while carefully reciting Hail Marys.

There are many different Bible translations, NRSV is one of them.

Psalm 137 is a song relating the longing for Zion (Jerusalem) by the Jews when exiled in Babylon. It testifies that they did not forget the songs, or psalms, of Zion though they were far from their homeland.

Ancient Babylon was a land full of false gods. This worship of many false gods had a great effect upon the hearts of the faithful Jews who had worshiped only the one true God without any kind of image. Instead of beholding the temple of their God Jehovah in all its beauty in Jerusalem, they saw the temples of these false gods and their idols throughout the land of Babylon.

Sincerely E