Explanatory Notes on the Whole Bible, by John Wesley, [1754-65], at sacred-texts.com
psa 137:1Sat - The usual posture of mourners.
psa 137:2Harps - Harps are here put for all instruments of musick.
psa 137:3A song - Such songs as you used to sing in the temple of Zion.
psa 137:4The Lord's - Those songs which were appointed by God to be sung only in his service.
psa 137:6If - If I do not value Jerusalem's prosperity more than all other delights.
psa 137:7The day - In the time of its destruction.
psa 137:8Happy - As being God's instrument to vindicate his honour, and execute his just judgments.