Psalms 137:2

Whether the request was in curiosity or derision, the answer intimates that a compliance was incongruous with their mournful feelings (Pr 25:20). 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.

We hanged our harps upon the willows in the midst thereof. The drooping branches appeared to weep as we did, and so we gave to them our instruments of music; the willows could as well make melody as we, for we had no mind for minstrelsy. In the midst of the willows, or in the midst of the rivers, or in the midst of Babylon, it matters little which, they hung their harps aloft—those harps which once in Zion's halls the soul of music shed. Better to hang them up than to dash them down: better to hang them on willows than profane them to the service of idols. Sad indeed is the child of sorrow when he grows weary of his harp, from which in better days he had been able to draw sweet solaces. Music hath charms to give unquiet spirits rest; but when the heart is sorely sad it only mocks the grief which flies to it. Men put away their instruments of mirth when a heavy cloud darkens their souls.

We hanged our harps upon the willows - The ערבים arabim or willows were very plentiful in Babylon. The great quantity of them that were on the banks of the Euphrates caused Isaiah, Isa 15:7, to call it the brook or river of willows. This is a most affecting picture. Perhaps resting themselves after toil, and wishing to spend their time religiously, they took their harps, and were about to sing one of the songs of Zion; but, reflecting on their own country, they became so filled with distress, that they unstrung their harps with one consent, and hung them on the willow bushes, and gave a general loose to their grief. Some of the Babylonians, who probably attended such meetings for the sake of the music, being present at the time here specified, desired them to sing one of Zion’s songs: this is affectingly told.

We hanged our harps upon the willows - The harps once used to accompany the songs of praise and the service of God in the temple; the harps with which they had sought to beguile their weary hours, and to console their sad spirits in their captivity. The word rendered “willows” - ערבים ‛ărâbiym - used only in the plural, denotes the willow or osier, so called from its white, silvery leaves. Gesenius, Lexicon. Compare Isa 15:7. It is probable that the weeping willow - the willow with long pendulous branches - is here referred to. Trees in desert lands spring up along the courses of the streams, and appear, in the wide desolation, as long and waving lines of green wherever the rivers wind along. The course of a stream can thus be marked by the prolonged line of meandering green in the desert as far as the eye can reach. It has been objected to the statement here that the willow is not now found in the neighborhood of ancient Babylon, but that the palm is the only tree which grows there. I saw, however, in 1852, in James’ Park in London, a willow-tree with a label on it, stating that it was taken from the site of ancient Babylon; and there seems no reason to doubt the correctness of the account. The willow may be less abundant there now than it was in former times, as is true of the palm. tree in Palestine, but there is no reason to doubt that it grew there. All that the psalm, however, would necessarily demand in a fair interpretation would be that there should have been even a single clump of these trees planted there, under which a little band of exiles may have seated themselves when they gave utterance to the plaintive language of this psalm. In the midst thereof - In the midst of Babylon; showing that this referred to the city proper. […]