Psalm 137
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.