Ps 136:7

“Then he turneth to God in prayer against the enemies of that city. "Remember, O Lord, the children of Edom" (ver. 7). Edom is the same who is also called Esau: for ye heard just now the words of the Apostle read, "Jacob have I loved, but Esau have I hated." ...Esau then signifieth all the carnal, Jacob all the spiritual. ...All carnal persons are enemies to spiritual persons, for all such, desiring present things, persecute those whom they see to long for things eternal. Against these the Psalmist, looking back to Jerusalem, and beseeching God that he may be delivered from captivity, saith-what? "Remember, O Lord, the children of Edom." Deliver us from carnal men, from those who imitate Esau, who are elder brethren, yet enemies. They were first-born, but the last-born have won the pre-eminence, for the lust of the flesh hath cast down the former, the contempt of lust hath lifted up the latter. The other live, and envy, and persecute. "In the day of Jerusalem." The day of Jerusalem, wherein it was tried, wherein it was held captive, or the day of Jerusalem's happiness, wherein it is freed, wherein it reaches its goal, wherein it is made partaker of eternity? "Remember," saith he, "O Lord," forget not those "who said, Rase it, rase it, even to the foundation thereof." Remember then, it means, that day wherein they willed to overthrow Jerusalem. For how great persecutions hath the Church suffered! How did the children of Edom, that is, carnal men, servants of the devil and his angels, who worshipped stocks and stones, and followed the lusts of the flesh, how did they say, "Extirpate the Christians, destroy the Christians, let not one remain, overthrow them even to the foundation!" Have not these things been said? And when they were said, the persecutors were rejected, the martyrs crowned. ...”

“Day. When Jerusalem was taken, or when it shall be re-established. (Haydock) — The Idumeans incited the Babylonians to destroy it entirely, and even cut in pieces such as had escaped, Abdias v. 11., and Jeremias xii. 6. — But Nabuchodonosor punished them five years afterwards, and Hircanus forced them to receive circumcision. (Josephus, [Antiquities?] x. 11., and xiii. 18.) (Calmet) — Isaias (xxi. 11.) denounced their ruin, as the psalmist does here. (Worthington) — St. Chrysostom thinks that the latter expresses the vindictive sentiments of the Jews: but he rather desires that God’s cause should be maintained in the manner in which He should judge best. The illusions of our own imagination and vanity are most dangerous and domestic enemies, as the Edomites sprung from the same stock as Israel. (Berthier)”

“The second part of the Psalm supplicates vengeance upon Edom and Babylon. We see from Obadiah's prophecy, which is taken up again by Jeremiah, how shamefully the Edomites, that brother-people related by descent to Israel and yet pre-eminently hostile to it, behaved in connection with the destruction of Jerusalem by the Chaldaeans as their malignant, rapacious, and inhuman helpers. The repeated imper. Piel ערוּ, from ערה (not imper. Kal from ערר, which would be ערוּ), ought to have been accented on the ult.; it is, however, in both cases accented on the first syllable, the pausal ערוּ (cf. כּלוּ in Psa 37:20, and also הסּוּ, Neh 8:11) giving rise to the same accentuation of the other (in order that two tone-syllables might not come together). The Pasek also stands between the two repeated words in order that they may be duly separated, and secures, moreover, to the guttural initial of the second ערוּ its distinct pronunciation (cf. Gen 26:28; Num 35:16). It is to be construed: lay bare, lay bare (as in Hab 3:13, cf. גּלּה in Mic 1:6) in it (Beth of the place), of in respect of it (Beth of the object), even to the foundation, i.e., raze it even to the ground, leave not one stone upon another. From the false brethren the imprecation turns to Babylon, the city of the imperial power of the world. The daughter, i.e., the population, of Babylon is addressed as השּׁדוּדה. It certainly seems the most natural to take this epithet as a designation of its doings which cry for vengeance. But it cannot in any case be translated: thou plunderer (Syriac like the Targum: bozuzto; Symmachus ἡ λῃστρίς), for שׁדד does not mean to rob and plunder, but to offer violence and to devastate. Therefore: thou devastator; but the word so pointed as we have it before us cannot have this signification: it ought to be השּׁדודה, like בּגודה in Jer 3:7, Jer 3:10, or השּׁדוּדה (with an unchangeable ā), corresponding to the Syriac active intensive form ālûṣo, oppressor, gōdûfo, slanderer, and the Arabic likewise active intensive form Arab. fâ‛ûl, e.g., fâshûs, a boaster, and also as an adjective: ǵôz fâshûs, empty nuts, cf. יקוּשׁ = יקושׁ, a fowler, like nâṭûr (נאטור), a field-watcher. The form as it stands is part. pass., and signifies προνενομευμένη (Aquila), vastata (Jerome). It is possible that this may be said in the sense of vastanda, although in this sense of a part. fut. pass. the participles of the Niphal (e.g., Ps 22:32; Psa 102:19) and of the Pual (Psa 18:4) are more commonly used. It cannot at any rate signify vastata in an historical sense, with reference to the destruction of Babylon by Darius Hystaspes (Hengstenberg); for Psa 137:7 only prays that the retribution may come: it cannot therefore as yet have been executed; but if השׁדודה signified the already devastated one, it must (at least in the main) have been executed already. It might be more readily understood as a prophetical representation of the executed judgment of devastation; but this prophetic rendering coincides with the imprecative: the imagination of the Semite when he utters a curse sees the future as a realized fact. "Didst thou see the smitten one (maḍrûb)," i.e., he whom God must smite? Thus the Arab inquires for a person who is detested. "Pursue him who is seized (ilḥaḳ el̇ma'chûdh)," i.e., him whom God must allow thee to seize! Thy speak thus inasmuch as the imagination at once anticipates the seizure at the same time with the pursuit. Just as here both maḍrûb and ma'chûdh are participles of Kasl, so therefore השּׁדוּודה may also have the sense of vastanda (which must be laid waste!). That which is then further desired for Babylon is the requital of that which it has done to Israel, Isa 47:6. It is the same penal destiny, comprehending the children also, which is predicted against it in Isa 13:16-18, as that which was to be executed by the Medes. The young children (with reference to עולל, עולל, vid., on Psa 8:3) are to be dashed to pieces in order that a new generation may not raise up again the world-wide dominion that has been overthrown, Isa 14:21. It is zeal for God that puts such harsh words into the mouth of the poet. "That which is Israel's excellency and special good fortune the believing Israelite desires to have bestowed upon the whole world, but for this very reason he desires to see the hostility of the present world of nations against the church of God broken" (Hofmann). On the other hand, it cannot be denied that the "blessed" of this Psalm is not suited to the mouth of the New Testament church. In the Old Testament the church as yet had the form of a nation, and the longing for the revelation of divine righteousness clothed itself accordingly in a warlike garb.”