The Neglected PsalmBy Rabbi Jack Abramowitz
This Psalm was recited referring prophetically to the destruction of the first Temple at the hands of the Babylonians, and the subsequent exile. In it, David speaks in the words of the Levites, who would be exiled from Jerusalem.
“We sat by the rivers of Babylonia and cried,” the Levites say. Their captors asked them to sing one of their famous songs, but they stashed their instruments in the trees to hide them. “How can we sing one of G-d’s songs in a land of idolatry?” they ask.
The Levites say that if they ever forget Jerusalem, and fail to place the memory of her destruction over their own joy, then their hands and tongues should stop working (so they will lose the ability to play their instruments and sing).
In the last three verses, David asks G-d to remember Edom and the day of Jerusalem’s destruction. (This either refers to the destruction of the second Temple at the hands of the Romans or the jubilation of the Biblical nation of Edom during the destruction of the first Temple.) Babylonia will be destroyed (by Darius the Mede) and they will be treated as harshly as they treated the nations they conquered.
The reason I refer to this as “The Neglected Psalm” is because, as well known as it is, it is not often recited at its designated time. Psalm 137 should be recited before bentching (reciting grace after meals) on weekdays, much the same way that Psalm 126 (“Shir HaMaalos”) is sung on Shabbos and holidays. For some reason, the practice is nowhere near as widespread.