PS 137 Probably this psalm was wrote toward the end of the Babylonish captivity. Herein the captives complain of the scoffs of their enemies, yet remember Jerusalem, and foresee the downfall of Babylon, ver. 1-9.
Verse 1. Sat - The usual posture of mourners.
Verse 2. Harps - Harps are here put for all instruments of musick.
Verse 3. A song - Such songs as you used to sing in the temple of Zion.
Verse 4. The Lord's - Those songs which were appointed by God to be sung only in his service.
Verse 6. If - If I do not value Jerusalem's prosperity more than all other delights.
Verse 7. The day - In the time of its destruction.
Verse 8. Happy - As being God's instrument to vindicate his honour, and execute his just judgments.