Psalms 137:4

How shall we sing the Lord's song - איך נשיר eich! nashir; O, we sing! Who does not hear the deep sigh in the strongly guttural sound of the original איך eich! wrung, as it were, from the bottom of the heart? Can We, in this state of slavery, - We, exiles, from our country, We, stripped of all our property, - We, reduced to contempt by our strong enemy, - We, deprived of our religious privileges, - We, insulted by our oppressors, - We, in the land of heathens, - We sing, or be mirthful in these circumstances? No: God does not expect it; man should not wish it; and it is base in our enemies to require it.

How shall we sing the Lord's song - The song designed to celebrate his praise; that is, appropriate to the worship of Yahweh.

In a strange land - Far from our home; far from the temple; exiles; captives: how can we find spirit in such circumstances to sing? How can we do that which would be indicative of what we do not feel, and cannot feel - joy and happiness! The idea is not that those psalms or songs would be profaned by being sung there, or that there would be anything improper in itself in singing them, but that it would be misplaced and incongruous to sing them in their circumstances. It would be doing violence to their own feelings; their feelings would not allow them to do it. There are states of mind when the language of joy is appropriate and natural; there are states where the heart is so sad that it cannot sing.

137:4 The Lord's — Those songs which were appointed by God to be sung only in his service.