Psalms 137:4

4. How shall we sing, etc. The Psalmist puts a lofty and magnanimous answer into the mouth of the Lord’s people to their insolent reproach, which is this, that they abstained from their songs, as from their legal sacrifices, because the land where they now were was polluted. The Chaldeans thought the Jews were bound down permanently to this place of their exile; the Psalmist, when he calls it a foreign land, suggests that it was but the place of their temporary stay. But the main idea is, that Chaldea was not worthy of the honor of having God’s praises sung in it. No doubt the children of God wherever they have lived have always been strangers and foreigners in the world, but the land of Canaan was the sacred rest provided for them, and the Psalmist well describes them as being foreigners and sojourners when they were in other climes. He would in this way have them to be always ready and prepared for their return, tacitly enforcing what Jeremiah had prophesied, when, in order to prevent them from forgetting their native country, he had definitely foretold the time during which their exile should last, (Jeremiah 25:11; Jeremiah 29:10.) He would in the meantime animate them to constancy, and have them not to coalesce with the Babylonians through motives of fear. In our own day under the Papacy, great as the danger may be to which the faithful expose themselves by not conforming to the example around them, the Holy Spirit makes use of such a barrier as this to separate them from sinful compliances. “Toutesfois le Sainct Esprit leur met ia comme une barre pour les separer de toute simulation perverse, comme aussi elle emporteroit impiete.” — Fr.