Darby's Synopsis: Psalm 137
J. N. Darby, Synopsis of the Books of the Bible · public domain
Read the text: Psalms 137
Remembrance of Zion in their past captivity
Psalm 137 refers, and alone does — to give the full history of Israel's sorrows — to Babylon, which has only a mystic fulfilment in the latter days, but has its importance, because at that time was the closing of the period of the divine presence in Jerusalem, and the setting up of the power of the Gentiles. But faith could not content itself in a strange land nor sing the Lord's songs there; for they were not a heavenly people — hence they turn to Jerusalem, which faith never forgets. Babylon is to be destroyed and her judgment is desired; Edom's enmity not forgotten. The object of the psalm is to bring out their attachment to Zion in their captivity; there was no separation of heart from it in the strange land.
Source
J. N. Darby, Synopsis of the Books of the Bible, text from STEM Publishing: https://www.stempublishing.com/authors/darby/synopsis/psalms/psalms137.html. Provenance on the sources page.