5. If I shall forget thee, O Jerusalem! This confirms what was said in the former verse, and leaves us in no difficulty to understand what the Psalmist meant by it. For here God's people declare, and with the solemnity of an oath, that the remembrance of the holy city would be ever engra-yen upon their hearts, and never, under any circumstances, effaced. Having spoken of song, and of the instruments of music, the Psalmist's appeal is made in terms which corre-spond -- that his hand would forager its cunning, and his tongue cleave to his palate, or the roof of his mouth. The meaning' is, that the Lord's people, while they mourn under personal trials, should be still more deeply affected by public calamities which befall the Church, it being' reasonable that the zeal of God's house should have the highest place in our hearts, and rise above all mere private considerations. The second part of the sixth verse some interpret -- If this be not my chief joy to see Jerusalem once more in a flourishing condition. Others -- Joy will never enter my heart more, till I be gladdened by the Church's restoration. Both meanings are in my opinion comprehended in the words of the Psalmist. The one cannot be separated from the other; for if we set Jerusalem above our chiefest joy, the height of this joy must arise from the consideration of its prosperity, and, if this be the case, the grief we feel under its calamities will be such as effectually to shut out all worldly joys.

7. Remember, O Jehovah! the children of Edom. Vengeance was to be executed upon the other neighboring nations which had conspired to destroy Jerusalem, so that they are all doubtless included here under the children of Edom, who are specified, a parr, for the whole, either because they showed more hatred and cruelty than the rest, or that theirs were not so easily borne, considering that they were brethren, and of one blood, being the posterity of Esau, and that the Israelites had, by God's commandment, spared the Edomites, when they devoted all beside them to destruction. (Deuteronomy 2:4.) It was, therefore, the height of cruelty in them to invite the Babylonians to destroy their own brethren, or fan the flames of their hostility. We are to notice, however, that the Psalmist does not break forth into these awful denunciations unadvisedly, but as God's herald, to confirm former prophecies. God both by Ezekiel and Jeremiah had predicted that he would punish the Edomites, (Ezekiel 25:13; Jeremiah 49:7; and Lamentations 4:21,22) and Obadiah distinctly gives the reason, answerable to what is here stated -- that they had conspired with the Babylonians. (Obadiah 1:11.) We know that God intended in this way to comfort and support the minds of the people under a calamity so very distressing, as that Jacob's election might have seemed to be rendered frustrate, should his descendants be treated with impunity in such a barbarous manner, by the posterity of Esau. The Psalmist prays, under the inspiration of the Spirit, that God would practically demonstrate the truth of this prediction. Anti when he says, Remember, O Jehovah! he would remind God's people of the promise to strengthen their belief in his avenging justice, and make them wait for the event with patience and submission. To pray for vengeance would have been unwarrantable, had not God pro-raised it, and had the party against whom it was sought not been reprobate and incurable; for as to others, even our greatest enemies, we should wish their amendment and reformation. The day of Jerusalem,, is a title given by him, and of frequent occurrence in Scripture, to the time of visitation, which had a divinely appointed and definite term.

8. O daughter of Babylon ⁴ laid waste! The Psalmist discerns the coming judgment of God, though not yet apparent, by the eye of faith, as the Apostle well calls faith "the beholding of things not seen." (Hebrews 11:1.) Incredible as it might appear that any calamity should overtake so mighty an empire as Babylon then was, and impregnable as it was generally considered to be, he sees in the glass of the Word its destruction and overthrow. He calls upon all God's people to do the same, and by faith from the elevation of heaven's oracles, to despise the pride of that abandoned city. If the divine promises inspire us with hope and confidence, and God's Spirit attemper our afflictions to the rule of his own uprightness, we shall lift up our heads in the lowest depths of affliction to which we may be east down, and glory in the fact that it is well with us in our worst distresses, and that our enemies are devoted to destruction. In declaring those to be happy who should pay back vengeance upon the Babylonians, he does not mean that the service done by the Medes and Persians, in itself met with the approbation of God; ⁵ for they were actuated in the war by ambition, insatiable covetousness, and unprincipled rivalry; but he declares that a war which was carried on in a manner under God's auspices, should be crowned with success. As God had determined to punish Babylon, he pronounced a blessing upon Cyrus and Darius, while on the other hand Jeremiah (Jeremiah 48:10) declares those cursed who should do the work of the Lord negligently, that is, fail in strenuously carrying out the work of desolation and destruction, to which God had called them as his hired executioners. It may seem to savor of cruelty, that he should wish the tender and innocent infants to be dashed and mangled upon the stones, but he does not speak under the impulse of personal feeling, and only employs words which God had himself authorized, so that this is but the declaration of a just judgment, as when our Lord says,

"With what measure ye mete, it shall be measured to you again." (Matthew 7:2.)

Isaiah (Isaiah 13:16) had issued a special prediction in reference to Babylon, which the Psalmist has doubtless here in his eye -- "Behold God has sharpened the iron, and bent the bows; he sends forth the Medes and Persians, which shall not regard silver and gold; they shall thirst for blood only," etc.