{d} If I forget thee, O Jerusalem, let my right hand forget her cunning.

(d) Even the faithful are touched by their particular griefs, yet the common sorrow of the Church is most grievous to them, and is such as they cannot but remember and lament.

Jamieson-Fausset-Brown Bible Commentary

5, 6. For joyful songs would imply forgetfulness of their desolated homes and fallen Church. The solemn imprecations on the hand and tongue, if thus forgetful, relate to the cunning or skill in playing, and the power of singing.

Matthew Henry's Concise Commentary

137:5-9 What we love, we love to think of. Those that rejoice in God, for his sake make Jerusalem their joy. They stedfastly resolved to keep up this affection. When suffering, we should recollect with godly sorrow our forfeited mercies, and our sins by which we lost them. If temporal advantages ever render a profession, the worst calamity has befallen him. Far be it from us to avenge ourselves; we will leave it to Him who has said, Vengeance is mine. Those that are glad at calamities, especially at the calamities of Jerusalem, shall not go unpunished. We cannot pray for promised success to the church of God without looking to, though we do not utter a prayer for, the ruin of her enemies. But let us call to mind to whose grace and finished salvation alone it is, that we have any hopes of being brought home to the heavenly Jerusalem.