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.
Verses 4–5
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.
Verses 8–9
Happy - As being God's instrument to vindicate his honour, and execute his just judgments.